Effect of ZrB2 and Fly Ash on Tribological and Mechanical Properties of Aluminium 7075-Based Metal Matrix Composite at Elevated Temperatures in Reciprocating Motion.

The aim of this study is to develop a novel class of hybrid metal matrix composite materials (HMMCs) using the ultrasonic-assisted stir casting method with varying weight percentages of zirconium diboride (1, 3, 5wt%) and two weight percentages of fly ash. X-ray diffraction (XRD) and EDAX are used to confirm the fabrication of proposed HMMCs. A scanning electron microscope (SEM) is used to see the distribution of ZrB2 and fly ash particles throughout the matrix. The mechanical properties like tensile strength and hardness of the composites were investigated. A linear reciprocating dry sliding wear test at temperatures 25 °C, 75 °C, 125 °C, and 175 °C is performed on a multi-tribometer. A Taguchi-based grey relational analysis is used to optimize the input parameters to analyse the wear properties of HMMCs. The grey relational analysis shows that five weight percentages of ZrB2 and two weight percentages of fly ash are the optimum input parameters for the lowest specific wear rate. Hardness is improved by 53.33%, and ultimate tensile strength (UTS) is enhanced by 23% for the inclusion of 5 weight percentages of zirconium diboride with 2% fly ash compared to AA7075 alloy. Tribological property like wear resistance is also enhanced with the increasing weight percentage of zirconium diboride. [ABSTRACT FROM AUTHOR]