Theory and application of a micro-scale abrasive wear test

A micro-scale abrasion test has recently been developed that allows measurement of the wear resistance of the surface regions of a material. The typical penetration depth is less than 30 mu m The test uses a simple mechanical and optical system and involves rotating a hard steel sphere against a specimen in the presence of small abrasive particles. The method has been used to investigate the wear resistance of thin PVD coatings (1 to 5 mu m), metallic glass ribbons, and paint films in addition to bulk samples of metals, ceramics, and glasses. The associated theory has been extended so that results may be obtained from any curved surface. This furthers its applicability to practical surface-engineered components such as twist drills, bearings, turbine blades, and biomedical prostheses. A detailed characterization of the experimental procedure has been undertaken to provide an understanding of the repeatability and sensitivity of the test. In a study of cutting-tool coatings, the wear resistance measured by this method has been shown to correlate with scratch test response and with the performance of coated end-mills in cutting tests.