Nanoscale Analyses of Wear Mechanisms

Abstract

This paper compares the usefulness of continuum mechanics with that of MD simulation for the analysis of abrasive wear mechanism in nanometer scale. The wear in repeated abrasive contact is also analyzed experimentally in nanoscale. In abrasive wear, there are three abrasive wear modes; cutting mode, wedge-forming mode and ploughing mode. Wear particles are generated by one pass of sliding in cutting mode or wedge forming mode, but no wear particle in ploughing mode. The generation mechanisms of these three abrasive wear modes have been well observed with SEM in micrometer scale and theoretically analyzed with continuum mechanics. Abrasive wear mode map has been established with these results. The predictions of abrasive wear modes by this map are compared in this paper with those by the MD simulations calculated for nanometer scale machining. The comparison shows that the prediction of nanoscale wear mode by the continuum mechanics agrees well with that by the MD simulation. In the case of ploughing mode, wear particles are generated only after repeated friction, which has been well observed experimentally in micrometer scale. This wear process is experimentally observed on carbon nitride coating, in this paper, in nanometer scale and its wear mechanism is confirmed as low cycle fatigue.