High Stress Abrasive Wear Mechanism of LM13-SiC Composite Under Varying Experimental Conditions.

An attempt has been made to understand the mechanism of material removal during two-body abrasive wear of Al-alloy (LM13)-SiC composite under varying experimental conditions through the wear surface and subsurface examination. It has been noted that the mechanisms of material removal during the wear process are primarily cutting and plowing, which lead to formation of continuous wear grooves. In the composite, SiC particles act as protrusions over the surface and protect the matrix from wear. But at higher applied load, coarser abrasive size, and larger sliding distances, some of the SiC particles get fractured into fine particles and scooped off from the wear surface leading to a higher wear rate. The subsurface studies show severe plastic deformation and finally formation of a mechanically mixed layer (MML) over the plastically deformed zone. The MML gets fractured during the wear process and finally removed by the formation of lateral and transverse cracking. The cracks are generally initiated at the interface of MML and the plastically deformed zone and propagate along the weaker region in MML. The material removal mechanism has been schematically presented in order to have a better understanding