the use of <sc>Bench Wear tests</sc> in Materials Development

TWO TYPES of bench wear tests employed by the General Motors Research Laboratories are described, and examples are given to illustrate the application of the tests to material development problems.

It is shown that correlation of a bench test with service may be achieved even when the laboratory test conditions do not appear to duplicate service conditions exactly. It is postulated that this behaviour is related to the formation of certain types of surface films during the wearing process. Some preliminary results are given of a study of the influence of lubricant type and material composition on the formation of anti-wear films.