New Opportunities to Determine the Rate of Wear of Materials at Friction by the Indentation Data

Abstract

The article is concerned with the determination of physical plasticity δH (the ratio of the plastic strain to the total strain) and yield stress σS by indentation and the application of these characteristics for analysis of the wear rate W during the friction. The experimental part of the work is performed on the AISI O2 and AISI D2 steels, the surface layers of which were hardened by combined thermomechanical treatment consisted of sequential use of laser heat treatment and ultrasonic impact treatment. For the metals, W is shown to be proportional to δH and inversely proportional to σS. The general scheme for the dependence of W on δH is proposed and based on experimental results for tool steels and hard alloys. For the steels, whose wear is caused by the plastic deformation, W increases with increasing δH, and it decreases conversely for hard alloys worn predominantly by the fracture mechanism. The use of physical plasticity δH and yield stress σS, which are calculated using the hardness and Young’s modulus, characterizes both the hardening extent and the wear rate of the surface layers in more full measure and more accurately than the hardness magnitude itself.

Keywords

• wear
• physical plasticity
• yield stress
• hardened surface layer
• hardness
• indentation