Experimental studies of different quenching media on mechanical and wear behavior of Al7075/SiC/Al2O3 hybrid composites

Abstract

The effects of SiC (Silicon Carbide) - Al2O3 (Aluminium Oxide) particle in the Al alloy on the mechanical and wear characteristics of stir-casted Composites have been reported. The Al7075 is reinforced with 2, 4, 6 and 8 wt. % of reinforcements (SiC + Al2O3) to manufacture the hybrid composite. Ceramic particulates were added into Al alloy to achieve the low wear rate and improved mechanical properties. Hardening of cast specimens was done at 480°C for the duration of 2 hrs and the specimens were quenched into two different quenching media (water and ice cubes). Finally, age-hardening was carried out at the temperature of 160°C for the duration of 4 hrs and cooled at room temperature. The tensile strength, hardness and wear behaviour of MMCs (metal matrix composites) were evaluated on the un-treated and heat treated composite. The tensile strength and hardness of MMCs increased by incorporating SiC-Al2O3 particulates. The wear behaviour of the MMCs containing SiC-Al2O3 particulates revealed high wear-resistance. The heattreatment had considerably improved the properties when compared to the non-heat treated composites. The composites with the highest tensile strength, hardness and enhanced wear resistance were found in the composites quenched in ice cubes. Worn-out surfaces of the composite specimens were studied by using SEM (Scanning Electron Microscopy) and EDS (Electron Dispersion Spectroscopy) analyses.