Mechanical Properties and Machinability of Aluminium and Aluminium-Silicon Carbide Composites Processed by Equal Channel Angular Pressing (ECAP)

Abstract

ABSTRACT The present work was aimed to investigate the mechanical and machining characteristics of the Equal Channel Angular Pressed (ECAP) aluminium and Al-SiC composites fabricated by stir casting process. Commercial pure aluminium, Al-5%SiC and Al-10%SiC were considered for the analysis. ECAP processes were performed with all the three varieties of materials in BC route. The microstructure, mechanical properties namely hardness, ductility, tensile strength and machinability of all the three materials were analysed before and after single and two passes of ECAP process. The hardness of the ECAPed pure aluminium with two passes was 4% higher than that of casted Al-5%SiC specimen. This result suggests that the ECAP of pure aluminium with suitable number of passes is recommended to replace the Al-SiC composites. Vickers hardness and tensile strength of the ECAPed Al-10%SiC composites were increased by 18% and 20% respectively when compared with as cast condition. Al-10%SiC outperformed the pure aluminium and Al-5%SiC as cast and ECAPed conditions in terms of tensile strength. However, the machining performance of Al-10%SiC was not as good as pure aluminium and Al-5%SiC. Severe plastic deformed Al-5%SiC produced good surface finish and lesser tool wear compared with the other two specimens at all conditions.