The effect of SiCp Content on Properties of Al-SiCp Composites Prepared by Stir Casting and Powder Metallurgy Routes: comparative study

Abstract

Aluminum based metal matrix composites reinforced with SiC_p are widely used in aerospace, military, and civil manufacturing industries because of their high strength, modulus, wear resistance and fatigue resistance. Present work aims to study the effect of SiC_p content on mechanical properties of Al–SiC_p composites prepared by two different processing routes, Stir Casting and Powder Metallurgy. Pure Al metal and SiC_p powder with (0,2.5,5,7.5and 10_wt% SiC) were combined by stir casting at 800°C and 100rpm stirring speed then poured in steel mold at 760°C. The same weight fractions of pure Al and SiC_p powders were mixed and cold pressed at 700MPa for 30s followed by sintering at 550°C for 5 hours. It was found that increasing SiC_p content increases both micro hardness, and wear resistance in both processing routes. The maximum mean hardness value of Al-SiC composite have reached (48.1 HV) and (41.87 HV) at (10_wt%SiC) for both stir casting and powder metallurgy composites. It was also found that compressive strength increased as SiC_p content increases. Microscopic examinations and (XRD) were used to consolidate and interpret the results.