Characterization of mixed and gross slip fretting wear regimes in Ti6Al4V interfaces at room temperature

Fretting wear is a destructive phenomenon that can accelerate crack initiation in vibrating components, leading to premature catastrophic failures. Among the most important characteristics of fretting, is the transition from mixed fretting wear to gross slip. Research has shown that mixed fretting wear is the most detrimental to fatigue life. In this paper, a study was conducted that characterized the critical normal loads and displacements corresponding to the mixed fretting regime boundary in Ti6Al4V interfaces. Experimental testing shows that there is a linear relationship between critical load and displacement. Knowing the corresponding loads and displacements that induce mixed fretting conditions, will allow for the predetermination of wear regime in future tests. Tests conducted at or near the critical values of load and displacement exhibited extreme galling and evidence of cold welding. These tests also initially displayed mixed fretting wear; however, a cycle dependent transition to gross slip occurred in some tests.