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Measurement Notes
Composites
Characterization of nanosized filled particles in polymeric systems: a review
Thick Composites: Part I:Mechanical Test Review, Part II: Cure Optimisation
Design requirements for bonded and bolted composite structures
Techniques for monitoring water absorption in fibre-reinforced polymer composites
Environmental and fatigue testing of fibre-reinforced polymer composites
Through-thickness testing of polymer matrix composites
Through-thickness tensile testing of polymer matrix composites
An overview of through-thickness test methods for polymer matrix composites
Accelerated weathering: performance testing of polymer matrix composites
An introduction to the properties of carbon nano-particle enhanced polymers
Author: Sims, G D, Saveedra, M
MN 10, June 2010
Towards a planar cruciform specimen for biaxial characterisation of polymer matrix composites (PMCs)
Gower, M R L, Shaw, R M
MN 9, July 2009
Measurement of residual stresses and strains in carbon fibre composites
Maxwell, A S, Broughton, W R, Lodeiro, M J, Shaw, R
Accelerated weathering: performance testing of polymer matrix composites
Broughton, W R, Pilkington, G D, Ratnakela, D K
DEPC-MN 047, March 2007
Through-thickness testing of polymer matrix composites
Broughton, W R, Gower, M R L, Lodeiro, M J, Shaw, R M
MATC(MN)06, May 2001
Environmental and fatigue testing of fibre-reinforced polymer composites
Broughton, W R, Lodeiro, M J
CMMT(MN)67, December 2000
Techniques for monitoring water absorption in fibre-reinforced polymer composites
Broughton, W R, Lodeiro, M J
CMMT(MN)064, December 2000
Environmental and fatigue testing of fibre bundles and impregnated strands
Broughton, W R, Lodeiro, M J
CMMT(MN)63, October 2000
Mapping indentation hardness
Roebuck B, Stewart M, Brooks M
DEPC-MN 030, November 2005
Polymer composites - rate dependent temperature calibration of dynamic mechanical analysers (DMA) for Tg measurements
Sims G D, Gnaniah, S J P
NPL Report, April 2005
Surfaces
Thermographic evaluation of thermal barrier coatings on contoured substrates
Nunn, J
Residual stresses in materials at high temperature: the link to hardness and scale exfoliation
Fry A T
MN 4, October 2008
Oxidation studies on miniaturised mechanical testpieces
Roebuck B
MN 1, April 2007
Measuring heat transfer through steam grown oxide scales
Fry A T, Roberts S, Chapman L
DEPC-MN 043, February 2007
The determination of residual stresses in coatings by coupon bending
Gee, M G, Newton, L
DEPC-MN 025, June 2005
Near surface strain measurements on quartz wafers and devices
Broughton W R, Fry A T, Mendels D A, Chunnilall C J
MATC(MN)52, July 2003
A Study of factors that may influence the quality of residual stress measurements from X-ray diffraction
Fry, A T
DEPC-MN 023, September 2005
Residual stress measurement: XRD depth profiling using successive material removal
Fry, A T
MATC(MN)34, September 2002
Evaluation of the repeatability of residual stress measurements using x-ray diffraction
Fry, A T
MATC(MN)19, May 2002
Mapping indentation hardness
Roebuck B, Stewart M, Brooks M
DEPC-MN 030, November 2005
Scratch edge chipping
Newton L, Gee M G, Morrell R
NPL Report DEPC-MN 026, August 2005
Wear
Measurement of wear with chromatic aberration probe
Mingard, K P, Gee, M G
DEPC-MN 045, March 2007
Ball cratering as a technique to evaluate microabrasion in corrosive media
Gant, A J
MATC(MN)39, October 2002
Stepwise erosion to determine the mechanisms of wear in gas borne particulate erosion
Gee, M G, McNaught,
MATC(MN)32, September 2002
An NPL rotating wheel abrasion test
Gee, M G, Gant, A J, Byrne, W P
CMMT(MN)030, November 1998
Mapping indentation hardness
Roebuck, B, Stewart, M, Brooks, M
DEPC-MN 030, November 2005
Hard Metals
WC/Co Hardmetals Rockwell - Vickers hardness comparison
Roebuck, B, Bennett, E G
DEPC-MN 011, December 2004
Hardmetals hardness and coercivity property maps
Roebuck, B
MATC(MN)14, March 2002
Ultrafine grained hardmetals grain size and distribution
Roebuck, B, Bennett, E G
MATC(MN)03, March 2001
Magnetic coercivity measurements for WC/Co hardmetals
Roebuck, B
CMMT(MN)042, May 1999
Hardmetals, property review.
Roebuck, B
CMMT(MN)036, February 1999
Low temperature properties of hardmetals.
Roebuck, B
CMMT(MN)004, August 1997
Mapping indentation hardness
Roebuck, B, Stewart, M, Brooks, M
DEPC-MN 030, November 2005
Microstructure mapping in high temperature compression testpieces
Mingard, K P, Bennett, E G, Ive, A J, Roebuck, B
NPL Report DEPC-MN 037, January 2006
Adhesives
Monitoring the effect of damage in bonded and bolted T-joints
Broughton, W R, Shaw, R M
MATC(MN)56, April 2004
Geometric and bolt position effects on the performance of bolted T-joints
Gower, M R L, Broughton, W R
MATC(MN)30, October 2002
Author(s):Gower, M R L, Broughton, W RSource:NPL Report MATC(MN)30, October 2002ISSN:1473-2742ISBN:NPL Doc. Ref: PDB: 3217 Document Type: NPL Report
Geometric and material property effects on the performance of adhesive T-joints
Crocker, L E, Broughton, W R
MATC(MN)29, October 2002
Optimisation of corona discharge surface treatment for improved adhesive bonding using design of experiments
Lodeiro, M J, Broughton, W R, Gnaniah, S
MATC(MN)25, August 2002
Assessment of surface characterisation techniques for adhesive bonds
Broughton, W R, Lodeiro, M J, Shaw, R M, Arranz, E, Gnaniah, S J P
MATC(MN)24, August 2002
Effects of specimen geometry on the strength of flexible adhesive joints
Broughton, W R, Attanz, E, Mera, R D, Duncan, B C
MATC(MN)11, July 2001
Geometric and material property effects on the strength of rubber-toughened adhesive joints.
Broughton, W R, Crocker, L E, Urquhart, J M
MATC(MN)10, August 2001
Mapping indentation hardness
Roebuck, B, Stewart, M, Brooks, M
DEPC-MN 030, November 2005
Polymeric Materials
In-process monitoring of the flow properties of polymer melts using on-line and in-line methods
Rides, M, Spitteler, P, Brown, C
NPL Report CMMT(MN)061, March 2000
Methods for characterising surface tension of hot melt adhesives
Nottay, J S, Rides, M
NPL Report DEPC-MN 013, March 2005
Review of methods for the characterisation of the dispersion in polymer nanocomposites
The effect of heat transfer coefficients and thermal conductivity on polymer processing simulation
Polymer flow incorporating slip and implications for polymer processing simulations
Measurement of heat transfer properties for polymer processing
Rides, M, Allen, C R G, Dawson, A
DEPC-MN 035, December 2005
Determining thermal conductivity by a differential scanning calorimetry method
Allen, C.R.G., Rides, M., Duncan, B.C.
DEPC-MN 031, November 2005
Polymer flow incorporating slip and implications for polymer processing simulations
Rides, M, Fleming, D, Allen, C R G
NPL Report DEPC-MN 040, March 2006
Guide to the measurement of the flow properties of polymers
Rides, M, Allen, C R G
NPL Report MATC(MN)43, December 2002
Guide to the measurement of the flow properties of polymers
Rides, M, Allen, C R G
NPL Report MATC(MN)42, December 2002
Improved melt flow rate measurements : an industrial case study
Rides, M, Dawson, A, Allen, C R G
NPL Report MATC(MN)38, October 2002
Measuring the extensional flow behaviour of polyethylenes for plastics processing
Rides, M, Allen, C R G
NPL Report MATC(MN)27, September 2002
Thermal properties of polymers part 1 : industrial guide to measurment by differential scanning calorimetry (DSC)
Allen, C R G, Hobbs, C B
NPL Report CMMT(MN)058, December 1999
Measuring the extensional flow properties of polymer melts using stretching methods
Rides, M, Allen, C R G
NPL Report CMMT(MN)41, April 1999
Measuring the extensional flow properties of polymer melts
Rides, M, Allen, C R G
NPL Report CMMT(MN)037, January 1999
Extensional flow properties of polymer melts using converging flow methods
Rides, M, Allen, C R G
NPL Report CMMT(MN)040, April 1999
The effects of thermal conductivity and heat transfer coefficients on polymer processing
Rides, M
NPL Report CMMT(MN)023, September 1998
Fuel Cells in Materials
Guide to durability testing of PEMFC electro catalysts
Hinds, G
NPL Report DEPC-MN 049, March 2007
Guides
Improving the consistency of particle size measurement.
Author: Mingard, K P, Morrell, R, Jackson, P*, Lawson, S*, Patel, S*, Buxton, R*
Source: Measurement Good Practice Guide No. 111, June 2009
ISSN: 1368-6550
Abstract: The principal causes of variability in particle size measurement, particularly in the sub-sieve range of 50 µm to sub 1 µm are summarised. The causes are illustrated with results of measurements from a series of round robins made to test reproducibility under different levels of prescription in the procedure followed. Improvements of over 50% in coefficient of variability for particle size fractions are shown to be possible when clear procedures are laid down for sampling, dispersion and handling even where different equipment constrains the exact procedure adopted. Users are encouraged to develop clear procedures based on the major factors described in the guide for each different powder encountered.
Code of practice for the measurement of bending in uniaxial low cycle fatigue testing.
Author: Kandil, F A
Source: Measurement Good Practice Guide No. 1, March 1998.
Abstract: The code of practice includes a method for measuring bending caused by misalignment of loading in uniaxial fatigue testing. The specific conditions are as consistent as practically possible with those encountered in the fatigue test. The method explores the effect of both plastic and elastic deformation on bending.
Measurement and analysis of creep in plastics.
Author: Tomlins, P E
Source: Measurement Good Practice Guide No. 2, November 1999.
Abstract: The guide describes procedures for obtaining creep data for plastic test pieces. It also describes a method for analysing these data in order to obtain parameters for a model which has the capacity to predict long-term creep performances.
Measuring flow stress in hot axisymmetric compression tests.
Author: Roebuck, B, Lord, J D, Brooks, M, Loveday, M S, Sellars, C M*, Evans, R W*
Source: Measurement Good Practice Guide No. 3, (Issue 2) ,2002.
Abstract: The guide describes good practice for measuring hot flow stress in metallic materials. It is applicable to hot (isothermal) uniaxial axisymmetric compression tests at medium to high rates of strain (10-4 to 102s-1) at deformation temperatures below the solidus.
Flexural strength testing of ceramics and hardmetals.
Author: Morrell, R
Source: Measurement Good Practice Guide No. 7, November 2007.
Abstract: Covering standardised tests, reasons for geometrical limitations, surface finish requirements, chamfering, test jig design requirements, sources of error (including friction and alignment problems), good test practice.
The measurement of palmqvist toughness for hard and brittle materials.
Author: Roebuck, B, Bennett, E G, Lay, L A, Morrell, R
Source: Measurement Good Practice Guide No. 9, 2008.
Abstract: Covering a draft procedure appropriate for hardmetals, background to successful testing, potential errors, correlations to plain-strain toughness tests discussion of problems of using the test on ceramic materials.
Residual stress in polymeric mouldings.
Author: Turnbull, A, Maxwell, A S, Pillai, S, White, J R*
Source: Measurement Good Practice Guide No. 10, October 1998.
Abstract: Thermoplastic polymer mouldings and thermoset mouldings often contain residual stresses which can cause distortion and may influence the fracture behaviour. This guide describes approaches to measurement of residual stress using layer removal, hole-drilling and chemical probe techniques. It will be of particular value to polymer processors, designers and materials testers.
Biaxial flexural strength testing of ceramic materials.
Author: Morrell, R
Source: Measurement Good Practice Guide No. 12, December 2007.
Abstract: Covering the advantages and disadvantages of the wide range of possible testing geometries including existing standards, with literature reference; frictional effects and other errors, and means of reducing them; large deflection analysis for thin discs (eg. substrates); measurement of elastic properties using disc resonance or impact excitation methods.
Fractography of brittle materials.
Author: Morrell, R
Source: Measurement Good Practice Guide No. 15, February 2008.
Abstract: Covering the methodology for viewing fractured fragments of brittle components such as high-strength ceramics and hardmetals, tracing the path of fracture and identifying the fracture origins. Many examples are given of different types of origin and their appearance when viewed using optical and scanning electron microscopes.
Measurement of the extensional flow properties of polymer melts using converging flow methods.
Author: Rides, M
Source: Measurement Good Practice Guide No. 16, March 1999.
Abstract: The extensional flow behaviour of polymer melts is very important in processing. This guide details the measurement of the extensional flow properties of polymer melts using converging flow methods. It presents an intercomparison of the predictions of various models, an assessment of uncertainties and a comparison with data obtained using a tensile method to demonstrate the validity of the converging flow approach.
The guide to the preparation and testing of bulk specimens.
Author: Dean, G
Source: Measurement Good Practice Guide No. 17, June 1999.
Abstract: This guide describes methods for preparing bulk specimens of adhesives and methods for testing these for the determination of mechanical property data needed for design. Emphasis is given in both specimens preparation and testing to the acquisition of accurate data. The guide is applicable to one-part adhesives that cure by heating and to two-part systems that must be mixed prior to curing.
Extensional flow properties of polymer melts using stretching flow methods.
Author: Rides, M
Source: Measurement Good Practice Guide No. 18, July 1999.
Abstract: The extensional flow behaviour of polymer melts is important in processing. This guide details the measurement of the extensional flow properties of polymer melts using tensile stretching methods. It describes practical considerations for measuring extensional flow behaviour, the analysis of the experimental data and an assessment of the uncertainties of the method.
Tests for advanced technical ceramic materials performance.
Author: Bennett, E G, Gee, M G, Lay, L A, Morrell, R, Roebuck, B
Source: Measurement Good Practice Guide No. 19, October 2007.
Abstract: The purpose of this guide is to give a contemporary account of the status of methods for determining the various performance characteristics of advanced technical ceramics, particularly those for mechanical applications, or where mechanical properties play an important ancillary role. Also covered are density/porosity determination, surface roughness measurement, thermal properties and corrosion testing. The background to the selected standard methods is briefly given, together with information on the relevance of the methods to end-uses. Where appropriate, the material classes for which the standardised methods need some modification or adaptation are discussed. Advice is given on typical sets of testing methods for quality assurance, materials selection and design data collection purposes. The Bibliography lists the current status of relevant standards.
Guide to mechanical tests for hardmetals.
Author: Roebuck, B, Gee, M G, Bennett, E G, Morrell, R
Source: Measurement Good Practice Guide No. 20 ,February 2009.
Abstract: Methods for the measurement of the mechanical properties of hardmetals at ambient temperatures are discussed. Current standards are assessed together with good measurement practice, including both routine procedures and research requirements. A comprehensive "property review" is included together with a summary of key microstructural parameters and their measurement. Comments are given on the discriminability of different mechanical test methods.
Microstructural measurement on ceramics and hardmetals.
Author: Morrell, R, Roebuck, B, Bennett, E G, Lay, L A
Source: Measurement Good Practice Guide No. 21, November 2007.
Abstract: This guide provides information on the role of microstructure on properties and performance of mechanical ceramics and hardmetals materials, together with the correct state of the art in preparing test-pieces for microstructural measurement and the methods for obtaining and analysing data.
The metallographic measurement of WC grain size.
Author: Roebuck, B, Bennett, E G
Source: Measurement Good Practice Guide No. 22, January 2000.
Abstract: This guide details recent developments in understanding the measurement issues for characterising the microstructures of hardmetals, particularly those ultrafine grain size. Analysis methods for modelling grain size distributions are also covered.
Method of measuring piezoelectric displacement in piezoelectric ceramics.
Author: Stewart, M, Cain, M G, Gee, M G
Source: Measurement Good Practice Guide No. 23, May 1999.
Abstract: This Good Practice Guide is intended to aid a user to perform displacement measurements on piezoelectric ceramic materials such as PZT (lead zirconium titanate) in either monolithic or multilayer form. Good measurement practice is described for several methods; fibre optic probes; laser interferometry; capacitance gauges; and strain gauges.
Finite element analysis of piezoelectric ceramics.
Author: Lowrie, F*, Stewart, M, Cain, M G
Source: Measurement Good Practice Guide No. 24, May 1999.
ISSN: 1368-6550
Abstract: This guide is intended to help people wanting to do finite element analysis of piezoelectric materials by answering some of the questions that are particular to piezoelectric materials. The document is not intended as a complete beginners guide for finite element analysis in general as it is better dealt with by the individual software producers. The guide is based around the commercial package ANSYS as this is a popular package amongst piezoelectric material users, however much of the information will still be useful to users of other finite element codes.
Measurement of high field dielectric properties of piezoelectric materials.
Author: Stewart, M, Cain, M G
Source: Measurement Good Practice Guide No. 25, May 1999.
Abstract: These guidelines are intended to enable a user to perform high field dielectric measurements on piezoelectric ceramic materials such as PZT (lead zirconium titanate). Some general advice on high field dielectric measurements is given, followed by a detailed description of three different measurement methods; Schering bridge; impedance analysis; and PE hysteresis loop methods.
Adhesive tack .
Author: Duncan, B C, Abbott, S G*, Roberts, R A*
Source: Measurement Good Practice Guide No. 26, July 1999.
Abstract: Adhesive tack is the property that controls the instantaneous formation of a bond when an adhesive and a surface are brought into contact. Although tack test methods are generally simple to perform, tack is sensitive to many experimental factors and obtaining reliable measurements can be a problem. This guide is intended to give guidance on the measurement of permanently tacky pressure sensitive adhesives (including tapes) and adhesives whose tack requires activation in some way. Standard test methods for pressure sensitive adhesives (rolling ball, loop tack, probe tack and quick stick) are discussed. A tack measurement method developed for the footwear industry is presented as a case study that illustrates the issues involved in measuring the tack of active adhesives.
Measuring flow stress in plane strain compression tests.
Author: Loveday, M S, Mahon, G J*, Roebuck, B, Sellars, C M*, van der Winden, M R*
Source: Measurement Good Practice Guide No. 27, (Issue 2) ,2002.
Abstract: This document has been produced to complement the Measurement Good Practice Guide No 3 which describes current best UK practice for measuring hot flow stress in metallic materials using Hot Axisymmetric Compression (HAC). This Guide is applicable to hot (isothermal) plane strain compression (PSC) tests at medium to high rates of strain at deformation temperatures below the solidus. Technical input to the document has been provided by a steering group comprising academic researchers, representatives of industrial users and producers of a wide range of engineering materials. An experimental programme was conducted during the preparation of this document to underpin the procedures in this guide.
Durability performance of adhesive joints.
Author: Broughton, W R
Source: Measurement Good Practice Guide No. 28, March 2000.
ISSN: 1368-6550
Abstract: Considerable effort is required in selecting adhesive systems and optimising process variables to maximise long-term strength retention under hostile environments. This document is intended to give guidance on the selection and use of test methods and environmental conditioning procedures (including accelerated testing) for generating design data and for quality assurance purposes. The document is primarily concerned with structural applications. Guidance is provided on specimen preparation, hot/wet conditioning and testing bulk adhesives and adhesive joints. Static, cyclic fatigue and creep rupture testing are covered. Consideration is given to the effect of material and geometric factors on joint performance under static, cyclic and creep loading, and hostile environments. The guide also provides a summary of surface analytical techniques, thermal analysis tools and non-destructive testing (NDE) techniques for inspecting bonded joints before, during and after testing.
Thermal analysis techniques for composites and adhesives.
Author: Mulligan, D R, Gnaniah, S J P, Sims, G D
Source: Measurement Good Practice Guide No. 32, September 2000.
ISSN: 1368-6550
Abstract: Thermal analysis techniques are widely used to aid the processing of composites and adhesives. These techniques can assist at all stages of processing from assessment of input materials, through evaluation of optimal processing conditions and quality control of the finished material, to assessment of performance characteristics. This Measurement Good Practice Guide covers three of the most common thermal analysis techniques. The advantages and disadvantages of each technique are identified and discussed. Following this discussion, recommendations are made on the choice of technique. A recommended procedure for each technique is presented together with a precision statement that provides a measure of uncertainty associated with these procedures. This publication has been superseded by Measurement Good Practice Guide No. 62
Piezoelectric resonance.
Author: Cain, M G, Stewart, M
Source: Measurement Good Practice Guide No. 33, January 2001.
ISSN: 1368-6550
Abstract: This Measurement Good Practice Guide is intended to help a user to perform resonance spectra measurements on piezoelectric ceramics. The phenomenon of resonance is introduced and linked to the evaluation of the piezoelectric matrix by appropriate choice of sample geometry, and data analysis method. The IEEE method and complex coefficient method is explained and compared with a worked example helping the user to understand the stages of measurement and analysis.
The measurement of surface texture using stylus instruments.
Author: Leach, R K
Source: Measurement Good Practice Guide No. 37, July 2001.
ISSN: 1368-6550
Abstract: This guide covers the measurement of surface texture using a stylus instrument. It describes the current international standards, introduces the terminology associated with surface texture measurement, and describes how to make measurements and how to interpret the results. The guide also covers the calibration of surface texture measuring instruments and informs the user of such instruments how to calculate measurement uncertainties.
Fibre reinforced plastic composites - machining of composites and specimen preparation.
Author: Davies, A*, Foreman, A*, Shaw, R M, Sims, G D
Source: Measurement Good Practice Guide No. 38, December 2001.
ISSN: 1368-6550
Abstract: The confidence placed in design data obtained from testing composite materials can depend greatly on the quality of the specimen used. Although, in principle the use of rectangular blanks as the staring point in most cases suggests specimen preparation is straightforward, there are many aspects that affect the quality of the measured data. For example, for unidirectional material loaded in either tension or compression, it is necessary to transfer the load into the specimen via protective tabs as it is not possible to use threaded or pin connections; or to use high grip pressures, due to the low interlaminar and transverse strength. Hence end tabs must be used that are well bonded to the specimen to avoid premature failure. In addition, for compression testing of these relatively thin laminates, as well as the test machine loading axially, the tabbed specimen must be symmetrical. The guide provides background information on all stages and aspects of machining and specimen preparation and reviews Good Practice in the preparation of specimens of composite materials, which in this context are polymeric matrices, both thermoset and thermoplastics, reinforced by fibres with a length greater than 7.5 mm in the starting material or compound. In recognition, of the wide range of materials involved and the range of machine equipment in use, the guide concentrates on good practice procedures and is not prescriptive on feed, speed etc. Included are experiences gained during the research programme covering machining trails and the results of industrial reviews of current practices with results given from Round-Robin participation. Also included, as an annex is a guide procedure that will be proposed as a future standard similar to ISO 1818 that deals with unreinforced or short and particulate reinforced polymers. Attention is also drawn to ISO 1268 for test plate preparation as the source of most test specimens. The preparation procedures have been incorporated onto a laminated card, which can be used as a check-list using a non-permanent marker, or photocopied for completion as part of the specimen preparation QA records.
Measuring piezoelectric d33 coefficents using the direct method.
Author: Stewart, M, Battrick, W, Cain, M G
Source: Measurement Good Practice Guide No. 44, June 2001.
ISSN: 1368-6550
Abstract: Although piezoelectric materials are often used as actuators in order to make small precise movements, it can be difficult to measure these displacements in an industrial environment. Consequently simpler methods have been sought to measure the piezoelectric activity, such as resonance methods, and measurements of the piezoelectric coefficient d33 using the direct method (often called the Berlincourt method). This good practice guide will examine the advantages and disadvantages of the method in detail and with some experimental validation using typical PZT ceramics examine the validity of using the data from this method to predict the displacement of materials in real conditions.
Characterisation of flexible adhesives for design.
Author: Duncan, B C, Crocker, L E
Source: Measurement Good Practice Guide No. 45, July 2001.
ISSN: 1368-6550
Abstract: Flexible adhesives, characterised by low modulus and large extensions to failure, have a long history of use in non-structural applications. However, the advantageous properties of flexible adhesives in sustaining large strains and more evenly distributing peel forces on the bonded substrates are leading to their use for structural joining applications. This is driving the need to improve the understanding of their mechanical properties, which has received little attention, in comparison to structural adhesives. The study of methods for characterising the deformation and failure of flexible adhesives has formed the core of the Flexible Adhesives project of the Performance of Adhesive Joints programme supported by the DTI. This Measurement Good Practice Guide describes methods for characterising the hyperelastic and visco-elastic properties required to predict the mechanical performance of a flexible adhesive layer in a bonded structure. The Guide also discusses some aspects of Finite Element modelling of flexible adhesives.
Preparation and testing of adhesive joints.
Author: Broughton, W R, Gower, M R L
Source: Measurement Good Practice Guide No. 47, September 2001.
ISSN: 1368-6550
Abstract: A number of factors, not included in written standards, can significantly affect the reliability (i.e. repeatability and reproducibility) of data obtained from testing adhesive joints. Factors, including specimen and machine alignment, processing variables, storage of materials and surface treatments need to be considered in addition to test parameters (e.g. displacement rate) and specimen dimensions that are generally covered in national and international standards. Careful consideration needs to be given to those factors that can significantly influence the strength and long-term performance of adhesive joints. This Good Practice Guide is intended to give guidance on the preparation and testing of adhesive joints, and the use of test methods under ambient and hostile environments (including accelerated ageing) for generating design data and for quality assurance purposes. Static, cyclic fatigue and creep rupture testing are also included. The document is primarily concerned with structural applications. The Good Practice Guide also includes the results from a three-stage round-robin exercise on Adhesive Joint Testing that was conducted in conjunction with UK industry to identify key preparation and testing issues.
The use of finite element methods for design with adhesives.
Author: Dean, G D, Crocker, L E
Source: Measurement Good Practice Guide No. 48, August 2001.
ISSN: 1368-6550
Abstract: This Good Practice Guide describes a range of materials models that are suitable for use with rigid (glassy) adhesives and adherends. Reference is made to models for linear elastic and viscoelastic behaviour, but emphasis is given to elastic-plastic models that are needed to describe the non-linear behaviour of tough adhesives. Some of the limitations in the use of these models with rubber-toughened adhesives are explained and illustrated with extensive data on a toughened epoxy. A new model that is still under development is introduced that includes the contribution to plastic deformation from cavitation of the rubber particles under certain stress states. Selected test methods for bulk and joint specimens are described that can be used to determine the property data and parameters required by these models.
General approach and procedures for unlubricated sliding wear tests.
Author: Gee, M G, Neale, M J*
Source: Measurement Good Practice Guide No. 51, January 2002.
ISSN: 1368-6550
Abstract: This Good Practice Guide aims to provide introductory guidance on unlubricated sliding wear testing. It contains a discussion on the most effective approach to friction and wear testing and considers the different aspects that should be taken into account when designing a programme of friction and wear testing under unlubricated sliding wear conditions. Specific guidance on how test conditions should be set and the procedures that should be used are given in Appendix A, and the results of an interlaboratory exercise that was used to validate the procedure are described in Appendix B.
Determination of residual stresses by X-ray diffraction.
Author: Fitzpatrick, M E*, Fry, A T, Holdway, P*, Kandil, F A, Shackleton, J*, Suominen, L
Source: Measurement Good Practice Guide No. 52, (Issue 2) ,September 2005.
ISSN: 1368-6550
Abstract: This guide is applicable to X-ray stress measurements on crystalline materials. There is currently no published standard for the measurement of residual stress by XRD. This guide has been developed therefore as a source of information and advice on the technique. It is based on results from two UK intercomparison exercises, detailed parameter investigations and discussions and input from XRD experts. The information is presented in separate sections which discuss the fundamental background of X-ray diffraction techniques, the different types of equipment that can be used, practical issues relating to the specimen, the measurement procedure itself and recommendation on how and what to record and report. The appendices provide further information on uncertainty evaluation and some recommendations regarding the data analysis techniques that are available. Where appropriate key points are highlighted in the text and summarised at the end of the document.
The measurement of residual stresses by the incremental hole drilling technique.
Author: Grant, P V, Lord, J D, Whitehead, P S*
Source: Measurement Good Practice Guide No. 53, (Issue 2) ,2006.
ISSN: 1368-6550
Abstract: Residual stresses can be defined as those stresses that remain in a body after manufacturing or processing in the absence of external forces or thermal gradients. Virtually all manufacturing and fabricating processes introduce residual stresses into the manufactured article and extreme service loading may also change the state of residual stress in the component. The effects of residual stress may be either beneficial or detrimental, depending upon the sign, magnitude and distribution of the stress. For improved process and product control, design, performance and modelling it is increasingly important to have rigorous experimental procedures to determine the residual stresses to the best possible accuracy. A wide variety of residual stress measurement techniques exist, but hole drilling is one of the most widely used. It is relatively simple, inexpensive, quick and versatile, and can be both laboratory-based and portable. However, achieving high quality, accurate stress data is not trivial. This guide provides both the inexperienced user and the expert with a practical guide to achieving better measurements. It draws together some background to the technique, discusses the current standards and highlights a number of key issues crucial to obtaining a good measurement, based on input from UK experts and some of the findings from a recent UK hole drilling residual stress intercomparison exercise. The currently available residual stress data analysis techniques are discussed, and a comprehensive bibliography of key references is included together with some information and links to UK hole drilling contacts and to relevant web sites, providing the reader with a valuable resource for further reading.
The scratch test: calibration, verification and the use of a certified reference material.
Author: Jennett, N M, Owen-Jones, S
Source: Measurement Good Practice Guide No. 54, December 2002.
ISSN: 1368-6550
Abstract: The scratch test is a simple engineering test method used to assess adhesive bonding between coatings and substrates. This guide aims to help you get the best out of your scratch tester. The Guide also explains the documents that you need to refer to if you want to carry out the test in a reproducible way. In particular, the Guide describes the new diamond-like carbon (DLC) coated certified material (CRM), BCR-692. Methods and strategies are described for using the CRM to compare results from different instruments and to enable the user to detect errors in the test, especially those caused by the tip of the stylus deviating from the required shape.
Rotating wheel abrasive wear testing.
Author: Gee, M G, Gant, A, Hutchings, I M*
Source: Measurement Good Practice Guide No. 55, March 2002.
ISSN: 1368-6550
Abstract: This Measurement Good Practice Guide aims to provide introductory guidance on abrasive wear testing. It contains a discussion on the most effective approach to wear testing and considers the different aspects that should be taken into account when designing a programme of friction and wear testing under abrasive wear conditions. Specific guidance on how test conditions should be set and the procedures that should be used are given in Appendix A.
General approach and procedures for erosive wear testing.
Author: Gee, M G, Hutchings, I M*
Source: Measurement Good Practice Guide No. 56, 2002.
ISSN: 1368-6550
Abstract: This Good Practice guide aims to provide guidance on erosive wear testing. It contains a description of the four common erosion test systems (gas jet; centrifugal accelerator; wind tunnel; whirling arm), and a discussion on the important variables in erosion such as particle impact velocity, particle impact angle, particle size, shape and material, and ambient temperature. A short review of techniques for data analysis and interpretation is also included. It also contains a discussion on the most effective approach to wear testing and considers the different aspects that should be be taken into account when designing a programme of friction and wear testing. In Annex A, specific guidance is given on gas jet erosion, on how test conditions should be set and the procedures that should be used.
Ball cratering or micro-abrasion wear testing of coatings.
Author: Gee, M G, Gant, A, Hutchings, I*, Bethke, R*, Schiffman, K*, Van Acker, K*, Poulat, S*, Gachon, Y*, von Stebut, J*
Source: Measurement Good Practice Guide No. 57, November 2002.
ISSN: 1368-6550
Abstract: This Measurement Good Practice Guide aims to provide introductory guidance on wear testing for coatings using the ball cratering or microabrasion wear test. Although the focus of the Guide is on abrasion testing, the use of ball cratering for unlubricated wear and friction testing is also covered. The guide also contains a discussion on the most effective approach to wear testing and considers the different aspects that should be taken into account when designing a programme of friction and wear testing. Specific guidance on how test conditions should be set and the procedures that should be used are given in Appendix A.
High temperature solid torsion tests.
Author: Roebuck, B, Loveday, M S, Chastel, Y*, Fiorucci, G*, dal Negro, T*
Source: Measurement Good Practice Guide No. 58, May 2003.
ISSN: 1368-6550
Abstract: This document outlines good measurement practice to be adopted for High Temperature Torsion tests on solid metallic materials. The Guide is applicable to hot (isothermal) tests at medium to high rates of strain (10-3 to 102 s-1) at deformation temperatures relevant to metal working practice. Technical input to the document has been provided by the steering group of a European SMT funded project on High Temperature Testing, TESTIFY, that contains representatives of industrial users and producers of a wide range of engineering materials as well as academic modellers. An experimental programme was conducted during the preparation of this document to underpin the procedures in this guide. It is anticipated that, in due course, a further version of this document could be produced that, in principle, could form the equivalent of a CEN or ISO Standard.
Multi-rate and extensional flow measurements using the melt flow rate instrument.
Author: Rides, M, Allen, C R G, Dawson, A
Source: Measurement Good Practice Guide No. 61, November 2002.
ISSN: 1368-6550
Abstract: This guide presents the procedures and analyses necessary to carry out testing using new methods based on the use of the melt flow rate equipment for characterising the shear and extensional flow behaviours of polymer melts. These methods are - multiple flow rate testing, obtained through the use of various loads, - the use of an additional short-die geometry to quantify separately shear and extensional flow effects, and - extrudate swell and draw-down measurements, to assess the materials extensional flow behaviour The multi-load test method will enable melt flow rate data to be extrapolated more reliably to higher shear rates. The use of the short die geometry and the measurement of extrudate draw-down will address the characterisation of the extensional flow behaviour of polymers that is often critical to their processability. These methods provide improved, yet affordable, materials quality control testing for polymers. Thus it is expected that the guide will be of particular value to those involved in quality control testing of materials, in particular where the production processes are dominated by extensional or stretching flows.
Thermal analysis techniques for composites and adhesives (second edition).
Author: Mulligan, D R, Gnaniah, S J P, Sims, G D
Source: Measurement Good Practice Guide No. 62 ,March 2003.
ISSN: 1368-6550
Abstract: This Measurement Good Practice Guide covers five thermal analysis techniques; DSC, TMDSC, DMA, DEA and DTUL. Each technique is described and measurement issues are discussed. Precision statements based on inter-laboratory testing are presented for DSC, TMDSC and DMA. Recommended procedures for each technique are included in the Guide. Recommendations are made for the choice of technique for the measurement of degree-of-cure and measurement of service temperature for composites and adhesives. Although these measurements are related, they present different measurement challenges and the effectiveness of each technique for these measurements is discussed.
Extensional flow properties of polymers using stretching flow methods.
Author: Rides, M, Allen, C R G
Source: Measurement Good Practice Guide No. 63, December 2002.
ISSN: 1368-6550
Abstract: In many forming processes the polymer melt undergoes predominantly extensional deformation, for example in blow moulding and film blowing. Furthermore, the extensional flow behaviour of melts differ significantly from their shear flow behaviour. Thus extensional flow measurement methods are necessary to appropriately characterise the melt behaviour. Such data can be used for the development and selection of materials, and for improving processing. This Guide discusses various issues related to the need for, and measurement of the extensional flow properties of polymer melts using stretching methods. It describes practical considerations for measuring extensional flow behaviour, including measurements at very high and low strain rates, and includes details on the analysis of the raw data and assessment of the effect of uncertainties on the measured values. To illustrate the measurement technique, typical data obtained using the NPL extensional rheometer are presented along with results obtained from an international intercomparison. This Guide is aimed at those carrying out, or intending to carry out, such testing or are building/modifying test equipment.
Fibre-reinforced plastic composites - qualification of composite materials.
Author: Gower, M R L, Sims, G D
Source: Measurement Good Practice Guide No. 64, April 2003.
ISSN: 1368-6550
Abstract: Both composite suppliers and end-users are affected by the high cost of composite materials qualification. Qualifying a product against different user specifications, introducing new materials and finding data for materials selection and preliminary design can all be prohibitively costly due to repetition of testing. This Measurement Good Practice Guide presents a Standard Qualification Plan (SQP) aimed at reducing the substantial costs involved in qualifying fibre-reinforced plastic composite materials. The SQP satisfies the minimum common requirements necessary to allow initial materials selection, quality control and preliminary design to be undertaken. Specifically, it provides guidance on test method selection, panel and specimen preparation and machining, specimen sampling, conditioning and test environments, and statistical analysis of measured data. The results of an associated round-robin validation exercise are briefly presented demonstrating the suitability and robustness of test methods included in the SQP. Collaboration with and support from national regulatory authorities such as the CAA is required, to encourage widespread use of the SQP. In addition, international collaboration (i.e. with the FAA) is key for harmonisation of qualification procedures.
Solderability testing of surface mount components and PCB pads.
Author: Zou, L, Lea, D, Hunt, C
Source: Measurement Good Practice Guide No. 66, February 2004.
ISSN: 1368-6550
Abstract: This document guides you to choose the correct test parameter settings for solderability testing of different type and size surface mount components and PCB pads. Pass/fail criteria are suggested and examples of good and bad solderability curves for each type component and PCB pad are given in the document to help you to judge the solderability of test component.
Characterising strength of adhesion.
Author: Duncan, B C, Broughton, W R
Source: Measurement Good Practice Guide No. 72, 2004.
ISSN: 1368-6550
Abstract: The design of adhesively bonded structures requires accurate material property data. These data are often best obtained from bulk test specimens. Such data can give an indication of the cohesive strength of the materials but designers also need to consider the strengths of the interfaces between the adhesive and substrates. Information on interface strengths is normally obtained from adhesives joint tests. However, the complexity of stress distributions in bonded joints leads to difficulties in obtaining quantitative interface strengths that are applicable to other loading configurations. As part of a DTI funded Measurements for Materials Systems project, Interfacial Adhesion Strength, a number of test methods for adhesion strength were studied as methods for quantifying adhesion strength. These test methods have been evaluated, in experimental and Finite Element (FE) studies, for their ability to quantify the strength of adhesion between adhesive and adherend. The properties of the surfaces being bonded are critical for the manufacture of strong, durable adhesive bonds. Techniques for inspecting surfaces have been assessed as part of this work. There is no universal surface or adhesion test suitable for all situations – methods need to be selected on the basis of the materials (adherend and adhesive), expected structural loading and service conditions, degree of accuracy required and budget (time and cost) for the assessment. Guidance is given to the selection and use of surface characterisation and adhesion strength test methods.
Laboratory test procedures to high temperature steam atmosphere.
Author: Osgerby, S, Fry, A T
Source: Measurement Good Practice Guide No. 74, 2005.
ISSN: 1368-6550
Abstract: Laboratory exposures cannot reproduce all the features present in service conditions. The experimentalist is faced with the conflict between increasing the complexity of laboratory tests to replicate service more closely and keeping testing costs low by maintaining a simple procedure. The influence of various experimental parameters, which can be controlled in the laboratory, on the steam oxidation response of materials is discussed and recommendations for best practice are proposed.
Cure monitoring techniques for polymer composites, adhesives and coatings.
Author: Lodeiro, M J, Mulligan, D R
Source: Measurement Good Practice Guide No. 75, February 2005.
ISSN: 1368-6550
Abstract: This Measurement Good Practice Guide covers real-time, on-line cure monitoring in the industrial processing of thermosetting polymer-based materials, such as fibre-reinforced composites, adhesives and coatings. The Guide focuses on the five most commercially well-developed cure monitoring techniques: thermal, ultrasonic, acoustic, dielectric and strain sensing. The procedure, theory and analysis for each measurement technique is described in detail and their respective sensitivities to important stages during cure processing discussed. Typical examples of obtainable results are demonstrated using laboratory investigations, with supporting evidence of their application to real environments, processes and problems being provided by three industrial case studies. Recommendations are made on the choice of technique and important considerations when making an appropriate selection. Finally, the overall benefits of adopting cure monitoring are highlighted. The Guide provides a consolidated source of information to help exploit cure-monitoring technology.
Guidelines for measuring anionic contamination of Printer Circuit Boards (PCB) and Circuit Assemblies (PCA) using ion chromatography.
Author: Zou, L, Brewin, A, Hunt, C
Source: Measurement Good Practice Guide No. 76, September 2004.
ISSN: 1368-6550
Abstract: This document provides the procedure to identify the level of anionic contamination residues on printed circuit boards (PCBs) and circuit assemblies (PCAs) using Ion Chromatography (IC). Recommendations for test parameter settings and sample preparation to optimise the IC system performance, are provided. Specific issues relevant to testing PCBs and PCAs (resin content in the flux, and solvent fraction in the extract solution), are discussed. Details are given on achieving robust and stable IC measurements when rosin is present in the extract samples, based on prefiltering. A chemical selective disposable cartridge is used to remove rosin from the sample stage, and an in-line trap column is used to prevent contamination of the analytical column. Since the use of a 75% IPA solution (as recommended in IPC TM650 2.3.28) causes background shift, the use of a low IPA content extraction solution is also strongly recommended, in order to eliminate rosin dissolved in the test samples.
Surface testing for bonding.
Author: Duncan, B C, Leatherdale, D*
Source: Measurement Good Practice Guide No. 77, December 2005.
ISSN: 1368-6550
Abstract: The manufacture of adhesive bonds requires suitably prepared substrates. As part of a DTI funded Measurements for Materials Systems project, Efficiency Improvements in Rapid Bonding Systems, methods for assessing the suitability of surfaces for bonding were investigated. Methods for determining roughness, wettability, absorbency and bonding performance are presented. Methods need to be selected on the basis of the materials (adherend and adhesive), bonding process, loading and service conditions, degree of accuracy required and budget (time and cost) for the assessment.
Assessment and criticality of defects and damage in materials systems.
Author: Gower, M R L, Sims, G D, Lee, R*, Frost, S*, Stone, M*, Wall, M*
Source: Measurement Good Practice Guide No. 78, June 2005.
ISSN: 1368-6550
Abstract: A defect criticality framework and assessment procedure for composite material systems has been proposed, based on the multi-level assessment philosophy contained within API (American Petroleum Industry) 579 - Recommended Practice for Fitness-For-Service and Continued Operation of Equipment. The basis for the framework detailed in this guide is a 3 Level approach which involves increasing levels of sophistication in the assessment approach, from operator to expert. For each level, guidance and recommendations have been provided as to the degree of knowledge and complexity required for non-destructive evaluation (NDE), defect classification, defect criticality assessment and materials characterisation. Four industrial case studies have been undertaken in order to demonstrate various aspects of the framework and to validate the approach proposed.
Surface tension and extrusion-based rheological characterisation of hot melt adhesives.
Author: Rides, M, Allen, C R G, Dawson, A, Nottay, J S
Source: Measurement Good Practice Guide No. 81, December 2005.
ISSN: 1368-6550
Abstract: This Guide presents guidance for good practice in measurement of the surface tension and the shear and extensional flow properties of hot melt adhesives. It covers: the measurement of surface tension of hot melt adhesives using the pendant drop method, the measurement of shear viscosity and entrance pressure drop by capillary extrusion rheometry, the measurement of melt flow rate behaviour using a simple extrusion rheometer, and the analysis of the melt flow rate results obtained using ‘long’ and ‘short’ dies to determine shear viscosity and entrance pressure drop data. Example results are presented to illustrate the above methods, and to enable comparison of capillary extrusion rheometry and melt flow rate data thereby demonstrating the applicability of the melt flow rate method. In particular, the rheological methods covered in this guide focus on high rate measurement.
Measurement and modelling of self-heating in piezoelectric materials and devices.
Author: Stewart, M, Cain, M G
Source: Measurement Good Practice Guide No. 84, February 2006.
ISSN: 1368-6550
Abstract: Failures due to thermal issues are common in high power piezoelectric devices. This Measurement Good Practice Guide aims to give engineers an understanding of the problems, where they occur and how to avoid them. The guide covers ways and methods to predict the temperature rise seen, based on simple analytical models and the use of Finite Element Models. It reviews all the previous methodologies that people have used, and introduces some new techniques, applying them in a series of case studies that embody most of the conditions that are seen in real systems. The thermal property data needed for the thermal models, such as specific heat capacity and thermal diffusivity are measured, along with a summary of findings by other workers.
Predicting and measuring the 'feel' of soft-touch thermoplastic elastomers .
Author: Tomlins, P, Petrie, H*, King, N*, Crocker, L E, Gee, M G, Dean, G D, Rides, M
Source: Measurement Good Practice Guide No. 86, 2006.
ISSN: 1368-6550
Abstract: This Guide presents guidance for good practice in the psychological assessment and physical characterisation of soft touch materials. It covers The establishment of sensory evaluation groups, Determination of a common vocabulary for psychological assessment, Determination of psychologically relevant physical characteristics of soft-touch materials, Methods for deriving psychophysical relationships, Predictions of the ‘hardness’ of soft-touch materials using mathematical models (Finite element analysis). Example results are presented to illustrate the above methods.
Prediction of the impact performance of plastics using finite element methods.
Author: Dean, G D, Crocker, L E
Source: Measurement Good Practice Guide No. 87, February 2006.
ISSN: 1368-6550
Abstract: This Guide describes the application of Finite Element Analysis (FEA) for predicting the impact performance of plastics and the measurement of input data. Three elastic-plastic materials models are introduced that are able to describe the large strain, non-linear behaviour of plastics when this is caused by yield and flow. These models are the von Mises and linear Drucker-Prager models available in FE packages and a new model that takes account of the influence of cavitation on plastic deformation. Limitations in the applicability of the first two models for describing the deformation behaviour of the copolymer are demonstrated. Test methods are described for the determination of property data and parameters required by these models for the simulation of impact performance using finite element methods.
Determination of residual stresses by magnetic methods.
Author: Buttle, D J*, Moorthy, V*, Shaw, B*, Lord, J D (ed)
Source: Measurement Good Practice Guide No. 88, 2006.
ISSN: 1368-6550
Abstract: Residual stresses can be defined as those stresses that remain in a body after manufacturing or processing in the absence of external forces or thermal gradients. Virtually all manufacturing and fabricating processes introduce residual stresses into the manufactured article and extreme service loading may also change the state of residual stress in the component. The effects of residual stress may be either beneficial or detrimental, depending upon the sign, magnitude and distribution of the stress. For improved process and product control, design, performance and modelling it is increasingly important to have rigorous experimental procedures to determine the residual stresses to the best possible accuracy. A wide variety of residual stress measurement techniques exist, but without experience or detailed knowledge it is difficult for the user to choose which method is most appropriate. This is the third NPL Good Practice Guide dealing with Residual Stress Measurement, the others, which are also available, focus on the X-ray Diffraction and Hole Drilling methods.
Slip flow measurement by capillary extrusion rheometry.
Author: Rides, M, Allen, C R G
Source: Measurement Good Practice Guide No. 90, 2006.
ISSN: 1368-6550
Abstract: This Guide presents guidance for good practice in measurement of the slip velocity of molten plastics by capillary extrusion rheometry. It: describes capillary extrusion rheometry testing and its application to the determination of slip velocities, provides guidance on the measurement of slip velocities, presents results of the measurement of slip velocities, including results from an intercomparison, and presents an uncertainty analysis of slip velocity measurement.
Elastic modulus measurement.
Author: Lord, J D, Morrell, R
Source: Measurement Good Practice Guide No. 98, February 2007.
ISSN: 1368-6550
Abstract: Elastic modulus is an intrinsic material property and a key parameter in engineering design and materials development. A wide range of test methods is available for measuring modulus, but there is currently some uncertainty within parts of the user community about the reliability of modulus data, to the extent that many use standard handbook values in their calculations and designs. This is not recommended and can be addressed through good experimental practice and careful measurement. Both static and dynamic modulus methods are covered in this Guide, presented in separate sections with details on the different test methods and on practical issues affecting the quality and accuracy of the measurement. The Good Practice Guide draws together some of the background to the techniques, discusses the current standards, and highlights a number of key factors crucial to obtaining good quality measurement. Examples are given where appropriate to highlight aspects of the test methodology, based both on measurements made at NPL and from a number of intercomparison exercises. Practical issues relevant to the current test methods are discussed, including test-piece preparation, alignment, strain measurement, data analysis methods, uncertainty budgets and the use of reference materials, together with a range of examples, and recommendations for obtaining good quality modulus data. Results presented show that it is possible to obtain good modulus data from the tensile test, but this generally requires a separate and dedicated test set-up using high quality averaging strain measurement and data analysis procedures, focusing only on the early part of the stress-strain curve. Dynamic methods are generally more versatile, and can be more readily applied to high temperature measurement and to brittle materials with good accuracy. In both cases, following the procedures recommended, accurate values of modulus can be realised, with typical uncertainties in the measured values as low as 1-2%
Non-destructive assessment of coating adhesion.
Author: Maxwell, A S, Rudlin, J*
Source: Measurement Good Practice Guide No. 100, June 2007.
ISSN: 1368-6550
Abstract: This document is a guide to the non-destructive assessment of coating adhesion both for the purposes of manufacturing quality assurance and onsite inspection. The different nondestructive techniques that are available are described highlighting their advantages and limitation. The key factors that should be taken into account when selecting a technique, for a particular application, are covered and short protocols on the use of the most promising techniques are provided.
The assessment of damage tolerance under long-term loading.
Author: Gower, M R L, Shaw, R M, Sims, G D
Source: Measurement Good Practice Guide No. 101, May 2007.
ISSN: 1368-6550
Abstract: This Guide provides best practice guidance for fatigue loading of composite materials and on the use of traditional static defect tolerance test methods under long-term fatigue loading. Guidance is also given on the use of non-destructive evaluation (NDE) techniques for defect growth detection, and in particular those techniques that can be used for real-time measurements. The Guide is primarily concerned with carbon and glass fibre-reinforced polymer composite material systems.
Absorption and diffusion of moisture in polymeric materials.
Author: Duncan, B C, Broughton, W R
Source: Measurement Good Practice Guide No. 102, March 2007.
ISSN: 1368-6550
Abstract: Accurate modelling of the absorption of moisture into engineering polymers is needed to design exposure procedures for durability assessment and carry out reliable lifetime predictions. This needs to be supported by good quality data obtained under representative conditions. This Guide describes methods for measuring the absorption and diffusion of moisture in polymeric materials, including plastics, adhesives and composites. Factors that will affect moisture absorption, including service conditions (temperature, pressure and stress) and the manufacture process (e.g. state of cure), are also covered.
Accelerated environmental ageing of polymeric materials.
Author: Broughton, W R, Maxwell, A S
Source: Measurement Good Practice Guide No. 103, March 2007.
ISSN: 1368-6550
Abstract: Whilst the life expectancy of products in non-demanding applications have traditionally been predicted from previous in-service experience (i.e. service conditions considered identical to those of which data already exists), long-term or critical applications require the use of accelerated ageing regimes to generate data commensurate with the engineering requirements and life expectancy of the component. This Good Practice Guide is intended to give guidance on accelerated ageing and performance testing of polymeric materials for generating design data and for quality assurance purposes. The document is primarily concerned with polymers (thermosets and thermoplastics) and fibre-reinforced plastics, and considers a range of hostile environments including artificial weathering, hot/wet and chemical (inc. solvents, caustic and acidic solutions) exposure.
Fatigue and creep testing of adhesives and thermoplastic joined systems.
Author: Broughton, W R, Dean, G D
Source: Measurement Good Practice Guide No. 104, March 2007.
ISSN: 1368-6550
Abstract: Welded thermoplastic and adhesively bonded joints are expected to retain a significant proportion of their load bearing capacity for the entire duration of the service life of the joined system. However, service conditions can often involve exposure to static and/or cyclic fatigue loading conditions. Fatigue damage can be particularly harmful to the structural integrity of bonded joints, shortening the life expectancy of the joined system by considerable margins, and is known to occur at relatively low stress levels, particularly in the presence of hostile environments. Similarly, premature failure can occur in bonded joints and welded thermoplastics under static loading conditions with deformation occurring at relatively low loads. This Good Practice Guide is intended to give guidance on fatigue testing of adhesively bonded joints and creep testing of bonded joints and welded thermoplastics for generating design data and for quality assurance purposes. The document is primarily concerned with structural adhesives and thermoplastics.
Good practice guide for quantifying microstructural heterogeneity in hot compression testpieces.
Author: Roebuck, B, Mingard, K P, Brooks, M, Palmiere, E J*, Wynne, B P*, Thomas, M J*, Bryant, M*, Evans, W J*
Source: Measurement Good Practice Guide No. 106, May 2008.
ISSN: 1368-6550
Abstract: This document describes good practice for measurements of material microstructure in hot compression testpieces such as AC (axisymmetric) and PSC (plane strain). It is applicable to hot (isothermal) compression tests at medium to high rates of strain (10-4 to 102 s-1) at deformation temperatures below the solidus. Technical input to the document has been provided by a steering group containing academic researchers and representatives of industrial users and producers of a range of engineering materials. An experimental and modelling programme has been conducted during the preparation of the document to underpin the recommendations in the guide.
Guide to the measurement of smooth surface topography using coherence scanning interferometry.
Author: Leach, R K, Brown, L*, Jiang, X*, Blunt, R*, Conroy, M*, Mauger, D*
Source: Measurement Good Practice Guide No. 108 ,April 2008.
ISSN: 1368-6550
Abstract: This guide describes good practice for the measurement and characterisation of smooth surface topography using coherence scanning interferometry (commonly referred to as vertical scanning white light interferometry). The guide is based on the measurement of the topography of semiconductors, epitaxial wafers and optical thin film coatings. However, the general guidelines described here can be applied to many flat, smooth surface topography measurements. For the purpose of this guide, the definition of a smooth surface is one that has an approximately random distribution of heights with a roughness (Sz) of less than 50 nm.
Good practice guide to reduce copper dissolution in lead-free assembly.
Author: Di Maio, D, Hunt, C P, Willis, B
Source: Measurement Good Practice Guide No. 110, December 2008.
ISSN: 1368-6550
Abstract: During a successful soldering operation to a copper surface a small amount of copper is dissolved to form a reliable interconnection and is perfectly normal. During the soldering operation copper is dissolved by tin to form a tin/copper intermetallic and the amount dissolved is dependent on the soldering process, solder alloy, surfaces to be joined, temperature, time and solder flow rate. Using lead-free alloys requires higher soldering temperatures and potentially longer contact times, and hence the propensity for higher dissolution of copper. A typical intermetallic produced with a tin/lead solder can range between 1-3µm. In the case of lead-free soldering process this thickness can increase above 5µm. The intermetallics are themselves soluble in solder, and hence potentially the overall copper dissolution rate is greater. Dissolution during lead-free soldering does not just impact copper pads on printed boards it can be a potential issue on thin copper wire, component terminations and hybrid metallisation. Examples of some typical problems previously experienced in industry are provided in this guide.
Improving the consistency of particle size measurement.
Author: Mingard, K P, Morrell, R, Jackson, P*, Lawson, S*, Patel, S*, Buxton, R*
Source: Measurement Good Practice Guide No. 111, June 2009.
ISSN: 1368-6550
Abstract: The principal causes of variability in particle size measurement, particularly in the sub-sieve range of 50 µm to sub 1 µm are summarised. The causes are illustrated with results of measurements from a series of round robins made to test reproducibility under different levels of prescription in the procedure followed. Improvements of over 50% in coefficient of variability for particle size fractions are shown to be possible when clear procedures are laid down for sampling, dispersion and handling even where different equipment constrains the exact procedure adopted. Users are encouraged to develop clear procedures based on the major factors described in the guide for each different powder encountered.
Improving single-crystal orientation determination for advanced nickel-based alloys.
Author: Clay, K*, Jackson, J D*, Quested, P N, Morrell, R
Source: Measurement Good Practice Guide No. 112, April 2009.
ISSN: 1368-6550
Abstract: This Good Practice Guide describes the determination of single-crystal orientation measurements for single-crystal nickel-base castings by back and side-reflection X-ray diffraction (Laue). These measurements check the quality of the castings against specifications set by the OEMs for the foundries. For quality control three parameters are determined: 1. The angle between a reference direction in the component, defining the preferred direction of solidification, and the closest <100> direction. (q). 2. Less commonly, the angle between a second reference direction in the plane perpendicular to the original reference direction (a) and/or a <001> direction (k). 3. For single crystals with more than one grain a measurement of the misorientation or disorientation between adjacent grains (R). The guide contains information about the definition of orientation parameters; principles of back-reflection and side-reflection Laue systems; calibration standards; system alignment; calibration; validation and uncertainty of measurements with a final section on making the measurements. The definition of primary angles is based upon European practice but a comparison with two definition conventions used in the USA is included.
The measurement of rough surface topography using coherence scanning interferometry.
Author: Petzing, J*, Coupland, J*, Leach, R K
Source: Measurement Good Practice Guide No. 116, December 2010.
ISSN: 1368-6550
Abstract: No abstract available
Best practice guide for thermocycling and reliability assessment of solder joints.
Author: Dusek, M, Hunt, C
Source: CMMT(A)274, July 2000
ISSN: 1361-4061
Abstract: This guide recommends best practice used for short-term accelerated thermal cycling as a method for assessing solder joint reliability. These techniques (shear testing, and electrical continuity measurements, complemented with microstructural investigations) are described.
Test methods for evaluating the reliability of PCB finishes using lead-free alloys - a guide.
Author: Dusek, M, Hunt, C
Source: MATC(A)107, April 2002
ISSN: 1473-2734
Abstract: This guide recommends and details best practice for short-term accelerated thermal cycling as a method of assessing the compatibility (and hence joint reliability) of lead-free solders with the materials of the PCB assembly. The assessment involves electrical continuity and shear test measurements complemented with microstructural observations. Data for various PCB materials assessed using the test method described are reported in MATC(A)89 ' Compatibility of lead-free solders with PCB materials'.
Static and dynamic calibrations of the nanotest at NPL.
Author: Aldrich-Smith, G, Jennett, N M
Source: DEPC-MPE 004, September 2004
ISSN: 1744-0262
Abstract: The NanoTest is an instrumented (nano)indentation system supplied by Micro Materials Ltd., Wrexham, U.K. This has report describes the procedures used for both static and dynamic calibrations of the NanoTest at NPL. Static calibrations for force, displacement, indenter area function, frame compliance are described. Dynamic calibrations for effective pendulum mass, damping coefficient and dynamic compliance are discussed. This document describes current best practice, an updated version will be produced on completion of this project.
Miniaturised testing.
Author: Roebuck, B, Brown, L, Banks, J, Brooks, R, Evans, M*
Source: DEPC-MPE 042, March 2007
ISSN: 1744-0262
Abstract: This report summarises outcomes of a three year collaborative project on miniaturised testing between the Materials Centre at NPL and the IRC in Computer Aided Engineering at the University of Wales, Swansea. It also notes comments and remarks at an Interest Group meeting at NPL on 28 March 2007. The collaborative project produced a numerical model of the small punch (SP) disc test and used this model to determine optimum testpiece and jig dimensions to maximise the sensitivity of the test. SP tests were conducted to validate the model. Uniaxial tests were undertaken in parallel with the SP tests, particularly on a thermally exposed ½Cr½Mo¼V steel, which demonstrated the ability of miniature testpieces to generate data that discriminated well between different material types. However, oxidation tests in the uniaxial test rig indicated that it would be sensible to conduct long term SP tests on Fe alloy samples in inert environments.
Non-invasive methods for monitoring microstructural condition of materials.
Author: Broughton, W R, Nunn, J
Source: DEPC-MPE 032, September 2006
ISSN: 1744-0262
Abstract: A critical evaluation has been carried out on non-invasive techniques for the detection of damage and the characterisation of microstructural changes that occur during the life cycle of materials from processing through to in-service operation. The techniques were grouped into 8 different categories. This review does not present the theory and full operation of the techniques in great detail, but notes their strengths and weaknesses and their range of application. This review is carried out from a generalist’s point of view and keeps foremost in mind the likely usefulness of individual techniques to the current and projected work carried out in the Division of Engineering and Process Control of the National Physical Laboratory. A short list comprising one candidate technique for damage assessment and four candidates for microstructural evaluation is presented.
Guide to the measurement of the flow properties of polymers.
Author: Rides, M, Allen, C R G
Source: MATC(MN)42, December 2002
ISSN: 1473-2742
Abstract: This guide includes a description of rheological techniques suitable for polymer melts, guidance on the selection of appropriate techniques, and sources of flow properties data and reference materials.
Guide to the measurement of extensional flow properties of polymers.
Author: Rides, M, Allen, C R G
Source: MATC(MN)43, December 2002
ISSN: 1473-2742
Abstract: This guide presents details of rheological techniques suitable for measuring the extensional flow properties of polymer melts.
Code of practice for dispensing electronic materials.
Author: Brewin, A, Zou, L, Hunt, C
Source: MATC(A)82, December 2001
ISSN: 1473-2734
Abstract: Robotic dispensing provides flexibility for electronics production not possible from screen-printing processes. As well as the application of solder paste and surface mount adhesive, dispensing systems are utilised with newer technologies such as the application of conductive adhesives, chip-on-board glob-tops and flip-chip underfills. This document gives practical guidance for the dispensing of these materials for printed circuit assembly production.
Development of test methods for measuring thick section tensile and compression properties of polymer matrix composites.
Author: Gower, M R L, Shaw, R M
Source: MN 6, April 2009
ISSN: 1754-3002
Abstract: The use of polymer matrix composites (PMCs) has primarily involved thin membrane structures, but recent developments have seen an expansion in the use of composite materials in structural applications involving thick sections in excess of 20 mm, often complex in shape. The general perception has been to consider through thickness properties with thick composites as problematical and difficult to measure, whereas in fact an equally important issue relates to the measurement of in-plane properties and the effect of physical size of test specimens on measured data. Although extensive developmental work has been undertaken worldwide into test methods and design procedures for in-plane properties of thin laminates, there are no standard test methods available that provide guidance on testing of thick composite sections. The approach generally adopted has been to use existing standards, developed for testing small laboratory-scale specimens, with non-standard (i.e. larger) specimen geometries. A major concern relates to whether data generated from standards for relatively thin specimens are equivalent to or representative of thick section mechanical behaviour. This Measurement Note details work undertaken to develop tension and compression test methods suitable for testing ~20 mm thick carbon fibre-reinforced plastic (CFRP) laminates in support of the design of composite components comprising of thick material sections. The work has been carried out to evaluate the scaling effect of increasing coupon size (in-plane dimensions and thickness) for distributed ply laminates and effect of ply-level scaling i.e. the blocking together of plies of the same orientation.
A review of residual stress measurement methods - a guide to technique selection.
Author: Kandil, F A, Lord, J D, Fry, A T, Grant, P V
Source: MATC(A)04, February 2001
ISSN: 1473-2734
Abstract: This review has been carried out as an activity in project CPM4.5, on the Methods of Measuring Residual Stress in Components, which is part of the CPM programme on Characterisation and Performance of Materials, funded by the Engineering Industries Directorate of the UK Department of Trade and Industry. It is the deliverable for Task 1. The purpose of this review is to provide an overview of some of the recent advances in the area of residual stress measurement and act as a summary document to aid technique selection. The intention is not to duplicate what has already been published, because a number of comprehensive reviews of residual stress measurement methods are already available, but to provide advice and guidance on some of the issues associated with the measurement of residual stress. The results of a UK industrial survey of current interests and expertise in residual stress measurement are presented, together with guidelines on technique selection and some advice on quantifying the measurement uncertainty and accuracy. The physical limitations of the various techniques currently used are also summarised.
In-plane testing of thick composites: a review.
Author: Broughton, W R
Source: DEPC-MPR 057, November 2006
ISSN: 1744-0270
Abstract: Recent developments have seen an expansion in the use of composite materials in structural applications involving thickness sections in excess of 20 mm, often complex in shape. The general perception has been to associate through-thickness properties with thick composites, whereas in fact an equally important issue relates to the measurement of in-plane properties and the effect of physical size of test specimens on measured data. Although extensive developmental work has been undertaken worldwide into test methods and design procedures for in-plane properties of thin laminates, there are no standard test methods available that provide guidance on testing of thick composite sections. The approach generally adopted has been to use existing standards, developed for testing small laboratory-scale specimens, with non-standard (i.e. larger) specimen geometries. A major concern relates to whether data generated from standards for relatively thin specimens are equivalent to or representative of thicksection mechanical behaviour. This report reviews key issues relating to mechanical testing of thick composite sections, highlighting issues that need to be resolved or better understood in order for these materials to fulfil their full market potential. The report covers tension, compression, shear, flexure and multi-axial loading conditions, environmental, impact and fatigue resistance, and issues relating to manufacture and inspection of thick laminates. Recommendations are provided as to future work required for test method development for thick composite laminates.
Rheology testing of solder pastes and conductive adhesives - a guide.
Author: Dusek, M, Zou, L, Hunt, C
Source: MATC(A)109, May 2002
ISSN: 1473-2734
Abstract: This guide discusses rheology practice for measuring solder paste and conductive adhesives. The main parameter, viscosity, can be measured to assess the flow properties of printing media. Additional tests can be conducted to assess the viscoeleastic properties of printing media as a response to an oscillating shear stress at various frequencies. The rheology of printing materials is a complex science and as illustrated in this report cannot be simplified to a single static viscosity reading.
Practical guide for designers and manufacturers of mouldings to reduce the risk of environment stress cracking.
Author: Maxwell, A S
Source: MATC(A)5, March 2001
ISSN: 1473-2734
Abstract: Environment Stress Cracking (ESC) is one of the main causes of failure of injection moulded plastic components. Failure occurs as a result of the accelerated fracture of polymeric materials due to the combined action of environmental exposure and stress. One of the main reasons for this is that designers often fail to take into account the influence of processing on the ESC susceptibility of the material. In particular, designers fail to appreciate the influence residual stresses may have upon the material properties. This guide outlines the basic steps that should be taken by designers and manufacturers to reduce the risk of ESC in injection moulded components.
Guide to ramped miniature thermomechanical tests for accelerated material discrimination in hardmetals.
Author: Roebuck, B, Gee, M G
Source: MATC(MN)15, March 2002
ISSN: 1473-2742
Abstract: No abstract available
Guide to wear problems and testing for industry.
Author: Neale, M J*, Gee, M G
Source: Tribology in Practice Series, Professional Engineering Publishing Ltd, London, 2000,
ISBN: 1860582877
Abstract: No abstract available
Guide to ramped miniature thermomechanical tests for accelerated material evaluation in powder metallurgy tool steels.
Author: Gant, A J, Roebuck, B
Source: MATC(MN)23, May 2002
ISSN: 1473-2742
Abstract: A miniature test system, using DC current heating has been evaluated for its ability to discriminate between different materials under thermo-mechanical regimes with conditions of ramping load or temperature to accelerate material response and failure characteristics.
Guide to durability testing of PEMFC electrocatalysts.
Author: Hinds, G
Source: DEPC-MN 049, March 2007
ISSN: 1744-3911
Avoidance of corrosion in plumbing systems
Author: Tiller, A K*
Source: Measurement Good Practice Guide No. 120, September 2011
ISSN: 1368-6550
Abstract: No abstract available
Corrosion control for buried pipelines
Author: Harvey, D W
Source: Measurement Good Practice Guide No. 121, September 2011
ISSN: 1368-6550
Guide to temporary corrosion protective
Author: Rogers, R
Source: Measurement Good Practice Guide No. 122, January 2012
ISSN: 1368-6550
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- NPL worked with a small UK company, HATS, to help them solve a measurement issue and improve their life-saving rehydration products. These products are used following natural disasters to support the local population.
- NPL is working with University College London on a fascinating project which investigates the dynamics of microbubbles, to see if they can be used as highly sensitive sensors in medical and industrial applications.
- NPL and BSI produce good practice guidance on the use of surface topography measurement instrumentation.
- In 2010 NPL's nanomaterials group completed a project appointed to us by the European Space Agency (ESA) to survey nanotechnology capabilities in Europe.
- NPL was the first to observe that nanotubes possess unique mechanical and transport properties which means they could act as super-efficient heat pipes, conducting heat away from nanoscale circuits.
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- UK SME demonstrates that their novel equipment for testing nano-structured materials complies with international standards.
- NPL has worked with industry specialists to develop a field guide for the application of fibre optic Bragg sensors used to measure strain on large industrial structures.
- This project attempted to identify and test materials that might improve turbine component resilience.
- NPL's Nanoanalysis team of scientists have broadened the understanding of controlled release drug systems by constructing layered organic films.
- Scientists at NPL are helping the electronics industry move to using lead-free solder alloys and meet regulatory changes, by researching how the potentially damaging 'tin pest' and 'tin whiskers' could affect them.
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