Subsurface morphological pattern, microstructure and wear response of Cu and Cu–Al alloys subjected to unidirectional and reciprocating sliding

Abstract

During reciprocating sliding of the Cu and Cu–Al alloys, we found that the characteristics of subsurface morphological patterns are intimately linked to dynamic recrystallization (DRX) structure generated by sliding. With the decreasing DRX grain size, the pattern changes from vortical to laminar feature at about 0.5 μm. The reciprocating sliding motion is favorable for producing morphologically vortical pattern and the DRX structure, while the occurrence of these processes is rare under unidirectional sliding. Additionally, the samples under unidirectional sliding exhibit higher wear resistance than those under reciprocating sliding, which may facilitate the development of delaminating tribolayer. The present results shed new insight into the relationship between morphological pattern, microstructure and wear behavior of materials under different sliding modes.