Effect of Equal Channel Angular Pressing on the Microstructure and Mechanical Properties of Al6061-SiCp Composites

Abstract

In the present study, Aluminium metal matrix composite with Al6061 matrix and SiC (10-30μm) particulate reinforcement of varying composition (2-10wt.%) were prepared by stir casting technique. Significant improvement in tensile strength and hardness was noticed as the wt.% of SiCp increases in as cast Al6061- SiC composites. The cast composites have been subjected to annealing treatment at a temperature of 400oC for 4 hours to homogenize the microstructure. The specimens have been prepared from these composites for Equal Channel Angular Pressing (ECAP). The ECAP process was carried out at room temperature using a die with channel angle of 120° and Bc route was adopted for successive passes. The effect of ECAP on the microstructure and mechanical properties of Al6061 -SiC composite is evaluated. After ECAP process, the size and distribution of the reinforcement particles are not changed but there is a significant reduction in the grain size of the matrix alloy was observed. The hardness and tension tests were conducted at room temperature as per ASTM standards. The results were compared with the base Al6061 material and as cast Al6061-SiC composites. There is a significant improvement in the hardness and the Ultimate tensile strength of ECAP processed composites.