Correlating surface topography of relaxed layer of ZA/ZrB₂ in situ composites to wear and friction

Abstract

In the present study, the correlation between the surface topography of relaxed layer and wear and friction has been investigated. For this purpose, the lubricating tribology and surface topography of insitu formed ZrB2 reinforced Zn-Al (ZA) composites have been studied. The wear and friction properties of composites have been evaluated on a pin-on disc tribometer under synthetic SAE20W40 motor oil. The worn surface has been studied by SEM, AFM, and profilometer. Results indicate the high wear resistance and low COF with smoother topography with ZrB2 reinforcement. The composite with 9 vol. % ZrB2 exhibits lower kurtosis and negative skewness values confirming the smoother topography with higher load carrying capacity. This composite exhibits little wear and COF even at higher loads and sliding distances in the presence of lubricant. A comparative study with existing tribological materials indicates that the present materials have huge potential to be used as bearings and bushings.