Wear of fluorapatite single crystals. V. Influence of environment on frictional behavior and surface failure.

In recent years, several investigations of the environment-sensitive mechanical behavior of certain crystalline, nonmetallic materials and glasses have been directed toward characterizing the wear behavior of these materials under conditions of sliding and drilling in active liquid environments. Buckley,' for example, examined the change in plastic deformation and friction coefficient of single crystals of calcium fluoride with sliding in water and oleic acid. Westwood and Goldheim2 and Westwood, Goldheim, and Lye3,4 have studied the environment-sensitive mechanical behavior of calcium fluoride and magnesium oxide. The purpose of this study was to evaluate the influence of liquid environments on the frictional behavior and surface failure of the basal plane of fluorapatite single crystals.