Dry sliding wear response of ZrB2-20vol.% MoSi2 composite

Abstract

Abrasive wear behavior of ZrB2- 20 vol.% MoSi2 composite has been studied using electroplated diamond disk as the counter facing body. The investigated composite has been prepared by hot pressing and it has been found to possess 97% of the theoretical density. The microstructure of the composite has been characterized using scanning electron microscopy (SEM), and results show that MoSi2 particles are uniformly distributed in the ZrB2 matrix. The Young’s modulus, Poisson’s ratio and fracture toughness of the investigated composite are 455 GPa, 0.11 and 4.7MPa√m, respectively. The effect of experimental conditions including applied load, sliding velocity and sliding distance on the tribological behavior of ZrB2- 20 vol.% MoSi2 composite have been investigated. Experimental results show that applied load and sliding velocity plays an important role on specific wear rate and surface roughness of worn surfaces. SEM is used to analyze the wear surface morphology and crack propagation to study the wear mechanism. The dominant mode of wear was identified as abrasion. Grain pullout and micro cracking control the prevailing wear mechanism.