Dry sliding wear behavior of Al 6082 metal matrix composites reinforced with red mud particles

Abstract

The present study aims at investigating the dry sliding wear behavior of Al-based 6082 metal matrix composites (AMMCs) reinforced with red mud particles by pin-on-disc configuration. AMMCs were fabricated with three different weight fractions of red mud particles ranging from 2 to 6% by using the stir-casting method. The friction coefficients and volumetric wear rates were continuously evaluated under normal loads of 10–30 N and sliding speed of 1.5 m s−1 for the constant sliding distance of 1000 m. Microstructural analysis indicated that red mud particles are more or less uniformly dispersed throughout the Al matrix with minimal agglomeration. Experimental data shows that microhardness and tensile strengths of both the as-cast and heat-treated composites are steadily improved by increasing the amount of reinforced red mud particles but at the cost of ductility. Analysis of worn surfaces revealed that delamination and abrasion are dominant wear mechanisms for the case of the heat-treated composites are whereas the adhesion wear mechanism for the base alloy. The composite containing 4% red mud particles experienced the lowest wear rate at a normal load of 30 N and sliding speed of 1.5 m s−1 as compared to other composites including the base alloy. While the composite with 2% red mud particles shows the lowest friction coefficient, base alloy exhibited the highest friction coefficient.