Effect of RE addition on wear behavior of an Al-6061 based hybrid composite

Abstract

Developments of new hybrid metal matrix composites are aimed to improve the wear behavior of these materials as of their vast engineering applications. Focus of present research endeavor is to investigate the wear performance of stir casted Al-6061 alloy based hybrid composites with Al2O3, SiC and CeO2 as reinforcement. Hybrid composites containing wt% of SiC and Al2O3 from 5% to 15% and CeO2 from 0.5% to 2.5% were fabricated. Wear tests were performed on hybrid composites with highest value of hardness and the base alloy. The load range for the testing was selected from 10 N to 30 N while range of sliding speed was chosen from 0.5 m/s to 2 m/s. Optimal value of hardness was found in hybrid composite reinforced with 7.5 wt% of both Al2O3/SiC and 2.5 wt% CeO2. Different wear mechanisms in samples were determined using SEM and EDS analysis of worn surfaces and wear debris. The results of wear test performed at sliding velocity of 0.5 m/s and load value of 10 N showed a significant improvement in wear rate of hybrid composites using cerium oxide particulates as reinforcement. The rate of wear in sample containing 7.5 wt% of both Al2O3 and SiC showed an improvement of around 38% in comparison to the base metal sample. Whereas, addition of 2.5 wt% of cerium oxides particulate in sample containing 7.5 wt% of Al2O3 and SiC led to 87.28% improvement in wear rate. It is concluded from the wear behavior analysis that surface of the hybrid composite experienced oxidation, abrasion and delamination wear at a test condition of load as 10 N and velocity as 0.5 m/s. Whereas, at the load of 20 N and 30 N with sliding velocity 1–2 m/s, the hybrid composite surface experienced delamination and plastic deformation wear.