Insitu synthesis of Al– MgAl ₂O ₄ composites and parametric optimization of tribological characteristics

Abstract

In this research, multiobjective optimization of tribological characteristics of Al–4Mg/in-situ MgAl ₂O ₄ composites fabricated via ultrasonic cavitation treatment assisted stir casting technique was carried out. Al–4Mg alloy dispersed with 0.5, 1 and 2 wt% in-situ MgAl ₂O ₄ was prepared and the microstructural and mechanical characterisation of the same has been carried out. Reinforcement addition, load and sliding velocity at 3 different levels was considered to attain the responses wear rate and friction coefficient. To identify optimised process condition for the developed composites to attain reduced friction coefficient and wear rate condition, grey analysis is tried out. Experimental results analysed via Grey relation and analysis of variance (ANOVA) proved wt.% of MgAl ₂O ₄ particles as significant parameter trailed by load and speed. Based on grey relational grade, minimal wear loss at lowest frictional coefficient can be attained for the composite dispersed with 2 wt% of in-situ MgAl ₂O ₄ at 20 N load and 2 m/s sliding velocity. Mechanisms behind the wear loss was analysed from worn out surface micrographs.