Surface wear study of composite spray coated steel

Abstract

In this investigation, a comparative study among different types of coating materials to improve the wear resistance of steel was conducted. There were three types of coating material, magnesium zirconate, aluminium bronze, and molybdenum, and mixtures of different percentages of them were used. The influences of load, velocity and counter surface roughness on each type were also determined. It was found that the addition of molybdenum to magnesium zirconate in a sufficient amount helped to increase its wear resistance in comparison to the wear behaviour of pure magnesium zirconate. Scanning electron microscopy and microhardness testing of longitudinal cross-sections of each of the materials were used to explore the reasons behind the interesting behaviour of these composites after abrasive wear testing. It was found that the reason behind the high wear resistance and high microhardness of the magnesium zirconate matrix after the addition of 10% molybdenum was the prevention of the pull out of magnesium zirconate particles. The abrasive wear mechanisms for the spray coated steel appear to be microcracking and microploughing.