Quasi-nano wear mechanism under repeated impact contact loading

Abstract

A new quasi-nano wear mechanism (QNWM) has been proposed in this paper based on the facts of wear curve turning under high energy impact contact loading. Its characteristic is that the wear rate of QNWM is only 1/10-1/3 that of delamination mechanism at the same energy density. The diameters of wear debris and pits on the worn surfaces fall into the quasinanometer scale (about 50–120 nm). The necessary and sufficient conditions, which bring about the QNWM, are: (i) the nanostructure (nano-crystalline + amorphous phase) in impact contact surface layer has formed by the intensive impact strain; (ii) the delamination wear cracking in sub-surface layer must be restrained; (iii) the microcracks of QNWM are produced in amorphous phase of surface nano-structure layer rather than in nano-crystalline.