MECHANICAL TESTS FOR ADVANCED TECHNICAL CERAMICS-DEVELOPMENT OF STANDARDISED PROCEDURES

Abstract Over the past decade, there has been an increasing need for validated procedures for testing for quality assurance, specification, materials selection and design data purposes. Many existing test methods are not always appropriate for modem materials, and this has led to the development of targeted standardised procedures, which are reliable, in which the errors are reduced to a minimum, and in which the scope of applicability is defined in materials terms. To aid this process, factors important to defining test reliability have been researched worldwide, resulting in better understanding of what a given type of test actually means. New standardised procedures have been, and continue to be, developed by standards committees, including CEN, ASTM and JIS, and work has started in ISO to agree worldwide standards. This paper reviews the development of mechanical test methods, including strength. fractography, fracture toughness and hardness testing standards. The advantages and disadvantages of the various methods are discussed and some of the problem areas are identified. The importance of interlaboratory testing, notably through European collaborative, CEN and VAMAS* projects, in quantifying experimental scatter and identifying potential errors in interpretation of procedures is demonstrated.