Evaluation of the extent of wear of articles

摘要

An article (40), such as a piece of manufacturing tooling, is modified prior to use by treating a portion of its surface (38) to be worn so that the treated surface worn more than a preselected amount has a different appearance than the treated surface worn less than the preselected amount, using a treatment process in which the treated surface is at least as wear resistant as the untreated surface. In one approach, the surface (38) is treated by implanting ions to a preselected depth. The ions are chosen so that the substrate has a different color at depths less than the preselected depth than does the substrate at depths greater than the preselected depth. After wear, the treated surface is visually inspected for color variations that indicate wear to more than the preselected depth. The surface treatment can also be accomplished by ion implanting or ion beam mixing a previously deposited surface coating.