In this investigation, a composite coating of alumina and yttria stabilized zirconia in equal proportion was developed on Al-6061 substrate using Atmospheric Plasma Spraying technique. Two commercially available powders of chemical composition Al 25Fe7Cr5Ni and Al 2 O 3 30(Ni 20Al) were used as bond coats. The coating samples were subjected to abrasive wear test as per ASTM G99. From the results it was found that wear rate and coefficient of friction depend on various parameters such as microstructure, surface roughness, porosity, coating thickness, and hardness. It was also found that the mechanism of wear is mainly due to abrasion and once the bond coat is exposed to the disc, it loses material by adhesion. As the coating systems possess α-Al 2 O 3 and ZrO 2 , they can be used for wear and heat resistant applications such as cylinder liner of internal combustion engines.

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A well-known AA7075 alloy used for most of the structural, aerospace, and automobile applications due to its excellent properties such as high strength, corrosion-resistant, and low density. To encourage industrialists, the physical and mechanical properties of the composite has to improve by reinforcing hard ceramic particles. In this investigation varying wt.% of hard ZrO2 (zirconium dioxide) particles (0.75, 1, 1.25, 1.5, 1.75, and 2 wt.%) are reinforced in AA7075 matrix alloy to form a composite. Motorized stir casting technique induced to distribute reinforcement particles homogeneously. The SEM micrographs reveal that uniform distribution of ZrO2 particles can be achieved after inducing motorized stir casting technique into the molten composite. The experimental test results revealed that the addition of ZrO2 particles enhanced the hardness and tensile strength of the AA7075/ZrO2 composite as compared to base matrix material. Among all composites, AA7075/1.5ZrO2 show higher hardness and strength.