Effect of h-Boron Nitrate on Microstructure and Mechanical Behavior of Al7075 Metal Matrix Composite Producing by Stir Casting Technique

Al7075 alloy reinforced with h-Boron Nitrate (BN) composites were processed by stir casting technique. The produced composite was subjected to microstructural studies using OLYMPUS -BX51M, tensile, hardness, density and wear tests. Tensile strength and hardness were found to increase by 12.8% and 20% respectively due to increased dislocation density with the addition of reinforcement. Microstructure showed grain refinement with reinforcement addition and reinforcement acts as nucleating sites with an approximately uniform distribution of reinforcements. Wear test was conducted with different loads 10, 20 and 30N for a sliding distance of 1500 m. Wear mass loss of composites showed improved wear resistance with variation in reinforcements. Worn surfaces were examined using SEM, which showed the presence of delamination, plough and debris on the surface. Due to the addition of low-density h-BN, the density of composites decreases with increase in reinforcement content.