Design and optimization process analysis of aluminum hybrid composites

Abstract

Aluminum Metal Matrix composites (AMMC) refer to a relatively recent class of aluminum alloy-based composites having an emphasis on lightweight and high performance. Compared to other MMC composites, AMMC has advantages like improved strength, higher stiffness, high-temperature properties, wear resistance, increased damping capacity coupled with a reduction in density. Applications of AMMC encompass a wide range of industrial components for automobile, aerospace, nuclear and electronic industries due to their above mentioned attractive properties. In this context, reinforcing the AMMC with suitable particulate materials such as chromium carbide (Cr3C2), an abrasive and graphite (Gr), a soft lubricant, can be advantageous over reinforced aluminum alloy due to their improved property combination, particularly high specific strength and elastic modulus coupled with good machinability, enhanced hardness and wear resistance. Hence, an attempt has been made in the present investigation to fabricate LM4/Cr3C2/Gr hybrid aluminum composites and to study theirmicrostructure, hardness and machining characteristics.Al LM4 alloy reinforced with Cr3C2 / Gr particles werefabricated using the stir casting method since it is an economical and welltestedfabricating technique for particulate matrix composites. LM4 alloy wasselected as the matrix material and reinforced with Cr3C2 in varying amounts(3, 6, 9 and 12 wt. %) along with constant 3 wt. % Gr to produce hybrid composites. Optical Microscopy (OM) studies of the hybrid LM4 compositesrevealed the uniform distribution of Cr3C2 and Gr in the matrix. Measureddensities of aluminum, Cr3C2, and Gr respectively were 2.70, 6.68 and 2.26g/cm3, the overall density of composites increased with increasing Cr3C2 newline