MATERIALS TESTING

measurement of the characteristics and behaviour of such substances as metals, ceramics, or plastics under various conditions. The data thus obtained can be used in specifying the suitability of materials for various applicationse.g., building or aircraft construction, machinery, or packaging. A full- or small-scale model of a proposed machine or structure may be tested. Alternatively, investigators may construct mathematical models that utilize known material characteristics and behaviour to predict capabilities of the structure. Materials testing breaks down into five major categories: mechanical testing; testing for thermal properties; testing for electrical properties; testing for resistance to corrosion, radiation, and biological deterioration; and nondestructive testing. Standard test methods have been established by such national and international bodies as the International Organization for Standardization (ISO), with headquarters in Geneva, and the American Society for Testing and Materials (ASTM), Philadelphia. Additional reading Zbigniew D. Jastrzebski, The Nature and Properties of Engineering Materials, 3rd ed. (1987), describes the qualitative mechanical behaviour of materials. W.D. Kingery, H.K. Bowen, and D.R. Uhlmann, Introduction to Ceramics, 2nd ed. (1976), illustrates the utilization of ceramic materials. Harmer E. Davis, George Earl Troxell, and George F.W. Hauck, The Testing of Engineering Materials, 4th ed. (1982), is a highly comprehensive and easily understood work offering detailed information on the various testing methods for use in the training of materials testing personnel. Discussions of testing techniques for various materials include three volumes in the Metals Handbook, 9th ed., prepared under the direction of the ASM International Handbook Committee: vol. 8, Mechanical Testing (1985), vol. 13, Corrosion (1987), and vol. 17, Nondestructive Evaluation and Quality Control (1989); Robert Baboian and Sheldon W. Dean (eds.), Corrosion Testing and Evaluation (1990); R.S. Sharpe, Research Techniques in Nondestructive Testing (1970 ); Don E. Bray and Roderick K. Stanley, Nondestructive Evaluation: A Tool for Design, Manufacturing, and Service (1989), examining the theory and practice of ultrasonic techniques, magnetic flux leakage techniques, radiographic methods, penetrant inspection, and eddy current concepts, with an extensive bibliography and examples of actual applications; Josef Krautkrmer and Herbert Krautkrmer, Ultrasonic Testing of Materials, 4th fully rev. ed. (1990), a classic text treating the use of ultrasonic waves to detect such defects as strength variations, nonbonding, and cavities; and International Advances in Nondestructive Testing (annual), addressing methods that currently have applications in various industries and new techniques for possible future applications. Kenneth E. Hofer, Jr. The Editors of the Encyclopdia Britannica