Tensile and Dry Sliding Wear Behavior of In-Situ Al3Zr + Al2O3-Reinforced Aluminum Metal Matrix Composites

Abstract

In the present study, aluminum-based in-situ intermetallic Al3Zr and Al2O3-reinforced metal matrix composites have been synthesized by direct melt reaction through stir casting of zirconium oxychloride (ZrOCl2·8H2O) powder in commercially pure aluminum. The in-situ reaction produces intermetallic Al3Zr needles that change to feathery morphology with increasing ZrOCl2·8H2O, while the Al2O3 is of fine globular shape. The tensile strengths of these composites increase with increasing volume percent reinforcements, attaining a peak value with 18 pct addition. The dry sliding wear behavior of the composites was evaluated with varying parameters, viz. sliding distance, normal load, and sliding velocities. The wear mechanisms are explained based on the microstructure, the topography of the worn surface, and the interfacial strength of the matrix and reinforcement. The tensile and wear properties are compared with widely used wear resistant hypereutectic Al-17 pct Si cast alloy. © 2015, The Minerals, Metals & Materials Society and ASM International.