Experimental investigation on surface roughness, tool wear and cutting force in turning of hybrid (Al7075 + SiC + Gr) metal matrix composites

Abstract

This paper presents a detailed study on optimization of turning parameters of Al7075/SiC/Gr metal matrix composites that are used for structural applications widely. The composite specimen containing a mixture of 90 wt.% of Al7075 and 10wt% of SiC and Gr is fabricated by stir casting process. The focus of the work is to identify the optimum weight fraction of reinforcement as well as optimizing the machining parameters. TOPSIS method of optimization is used to predict the optimum composition of reinforcement and the turning parameters like feed, speed and depth of cut. L27 orthogonal array (OA) design is used to carry out the turning experiments. As per TOPSIS analysis, minimum speed of 40 m/min, feed rate of 0.100 mm/rev, high depth of cut of 0.3 mm and material composition of 3%SiC + 7%Gr were found as optimal levels. SEM analysis is also carried out to study microstructural variations after machining. The confirmation test revealed the improvement in surface finish as 16.02% while the tool wear and cutting force are reduced by 22% and 32.30% respectively.

Keywords

• Aluminum
• Composite
• Turning
• Optimization
• Surface roughness and TOPSIS