Characterising the mechanical properties and performance of advanced materials
Our research covers a wide range of test types and materials, developing new methods to characterise advanced materials across the nano-micro-macro-structural scales, for both in-operando and ex-operando situations. We develop international standards to ensure our techniques are accepted by governing bodies to qualify materials for use in demanding environments, and understanding of the mechanisms which control the performance of the material.
Macro scale testing - for polymer composite materials
We are carrying out research into new test methods and procedures, so that we have the capability to support industry to test new materials or for new applications. This includes:
Micro scale testing - for metallic materials
We are understanding the microstructure of materials and the testing which is needed, including:
- Development of high temperature resistivity measurements using the NPL Electro Thermo Mechanical Test System (ETMT) to enable improved quantification of strain measurement and phase changes in alloys, hard metals and nuclear graphite
- Comparison and validation of micro-mechanical tests against standard macro-mechanical tests for course grained and complex microstructured materials. This will help establish whether conventional test methods are appropriate for additively manufactured materials and to determine best practice for testing complex thin walled parts, when samples are machined directly from the finished component.
- Development of methods for the measurement of residual stress within a microstructure using ion beam hole or slot milling. This work supports an underlying theme of comparing surface residual stress values with subsurface measurements, comparing x-ray diffraction, FIB hole drilling, conventional hole drilling and conventional mechanical testing
Nano scale testing
We are developing a high temperature nanoindentation apparatus, in collaboration with a UK manufacturer, which will be to produce reliable procedures to determine the surface condition of materials at temperatures up to 900 °C and extend the understanding of their performance in harsh environments.
Test methods for the use of an in situ indenter apparatus within an electron microscope are being developed. Pillar and cantilever manufacture methods using focused ion beam milling are being studied with emphasis on structural damage due to ion implantation, true sample geometry variations, microstructural variation and substrate compliance.
Although some of these test methods have been developed for particular materials, they may also be applicable to other classes of material.