National Physical Laboratory

Mechanical Testing: Ceramics & Hardmetals


Flexural strength measurements to EN 843-1/ASTM C1161 in four-point bending (spans 20/40 mm) at room temperature using a steel testing jig, and EN 820-1 at high temperature (to 1500 °C) using alumina or silicon carbide testing jig. Other test-piece spans and dimensions by negotiation.

Flexural creep measurements to EN 820-4 in four-point bending (spans 20/40 mm) to 1500 °C using an alumina or silicon carbide testing jig, air atmosphere.

Fracture toughness measurements by single-edge pre-cracked beam , chevron notch beam (CNB, CEN TS 14425-3), surface crack in flexure (SCF), single-edge vee-notch beam (SEVNB, CEN TS 14425-5).

Elastic modulus measurements to EN 843-2 by beam flexure, ultrasonic or impact excitation methods. The last of these can be performed on bars or discs to elevated temperature, yielding Young modulus, shear modulus and Poisson ratio. Hardness, HV1, HK2, HK1, HR45N to EN 843-4.

Fatigue testing, flexure, room temperature, up to 10 Hz. We are particularly set up for ceramic orthopaedic component testing to US FDA and ISO standard requirements.


Flexural strength measurements to ISO 3327 (rectangular or round test-pieces, three-point bending) or modified versions thereof, including four-point bending cf. ceramics

Fracture toughness testing, including Palmqvist crack length method.

Elastic modulus measurements using beam flexure, ultrasonic and impact excitation methods. The last of these can be performed on bars or discs to elevated temperature, yielding Young modulus, shear modulus and Poisson ratio.

Hardness to Rockwell ‘A’ and ‘C’ scales, HV30, HV100

Abrasive wear testing to ASTM B611 and ASTM G65 methods Fatigue testing using notched flexural beams

High-temperature testing using the ETMT: uniaxial, isothermal fatigue or TMF PM materials

In addition to the hardmetal test methods, any of the standard metals tests can be conducted as appropriate.

Wear and friction testing facilities for undertaking wear test investigations on bulk materials and coatings, including: ASTM B611: suitable as a ranking tool for hardmetals for severe wet abrasive wear conditions. ASTM G65: suitable as a ranking tool for any bulk material for medium abrasion conditions in wet or dry conditions. The pH of the wet condition can be modified as required.

Microabrasion test: a rotating steel ball fed with fine abrasive slurry pressed against the test-piece; suitable for fine-scale or mild wear, and suitable for coatings. This test can also be used for the crater grinding method of measuring coating thickness. Erosion testing: an air jet method using silica sand abrasive with variable incidence angle. Pin or ball on disc testing: a unidirectional sliding wear test with controllable loading and speed – suitable for dry sliding conditions. Reciprocating pin or ball on plate method: a bi-directional sliding wear test suitable for reciprocating motion, with controllable load and speed.

Ring on ring testing: a system based on matched rings, or continuous ring against segmented ring, capable of reaching high temperatures in controlled atmospheres. Hot reciprocating friction rig: capable of slow reciprocating sliding of contacts at high temperatures in air to study effects of temperature and oxidation on contact properties.

For more information: Ken Mingard

Last Updated: 25 Apr 2012
Created: 25 Jul 2007


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