Preparation and Mechanical Characterization of Stir Cast Hybrid Al7075-Al<sub>2</sub>O<sub>3 </sub>-B<sub>4</sub>C Metal Matrix Composites

Abstract

A hybrid Al7075 metal matrix composites have been fabricated through liquid metallurgy route (Stir Casting method) using Al 2 O 3 and B 4 C as reinforcement materials. The effect of weight percentage of reinforcement materials on mechanical properties of the composites have been studied by varying the weight percentage of Al 2 O 3 as 3, 6, 9, 12 and 15% while keeping constant weight percentage of B 4 C (3%). The as-cast microstructure, tensile strength, micro and macro hardness of the fabricated hybrid composites have been studied. The mechanical properties of the prepared composites were increased with increasing the weight percentage of the reinforcement in the composite. The maximum tensile strength, micro-hardness and macro-hardness of 309 MPa, 140 VHN, and 112 BHN, respectively, were obtained for a hybrid Al7075 matrix composite containing 15% Al 2 O 3 and 3% B 4 C.