Effects of addition of Titanium Diboride and Graphite Particulate Reinforcements on Physical, Mechanical and Tribological properties of Al6061 Alloy based Hybrid Metal Matrix Composites

Abstract

ABSTRACT The present study is aimed at fabricating and determining the physical, mechanical, and tribological properties of Al6061 alloy reinforced with Titanium Diboride and Graphite particles. The different weight percentages of hybrid particles (Titanium Diboride – Graphite) dispersed in the Al6061 matrix for fabricating hybrid metal matrix composites (HMMCs) using a stir casting method. The amount of titanium diboride reinforcement addition in the Al6061 matrix was in the range from 0 to 6 wt% whereas the fixed graphite reinforcement of 4 wt% was added. Optical Microscopy, Scanning Electron Microscopy and Energy Dispersive Microscopy studies were used to investigate the microstructure of the developed composite materials. The uniform distribution of reinforcement particulates in the matrix was observed. The addition of particulate reinforcements results in the enhancements of the mechanical properties such as density, hardness, with the expense of elongation. The tribological dry sliding wear experiments were carried out using a pin-on-disc tribometer. The Al6061-6%TiB2-4%Gr HMMCs reinforced composites exhibited the highest hardness and ultimate tensile strength and the lowest percentage elongation. Also, Al6061-6 percent TiB2-4%Gr samples had the best wear resistance. The increase in bonding by adding the optimum weight percentages of hybrid particles in the matrix could be the reason for this. The pristine Al6061 matrix exhibited the opposite trend.