The Measurement of Wear Damage

Abstract

The good qualitative understanding of the processes of, for example, fretting wear which now exists has not led to good quantitative descriptions of predictive value. One reason for this has been the very high cost, or complete non-availability, of measurement techniques having the precision necessary to characterize the damage, especially during the early stages of wear. Weight loss has been, and remains, the major method, although profilometry-based mapping has also been tried. Here these two approaches are critically compared in terms of potential precision and information capability. Other profilometry methods which reduce costs by relaxing the need for relocation and full mapping while maintaining a reasonably high information content are proposed and examined practically. It is concluded that for routine work weighing remains the most cost effective method but that the simpler profile-based assessments have better precision and are quite practicable. Their use is particularly relevant to the early stages of wear.