Optimization of operation parameters in machining of functionally graded metal matrix composite using TOPSIS

Abstract

Aluminium Functionally Graded Composites are the leading engineering materials due to its different gradient properties within the single element. Machining is one of the major challenging subjects in the functionally graded materials due to its gradient dissemination hard ceramic particles. The present work aims to manufacture Aluminium reinforced with 20 wt% SiC Functionally Graded Metal Matrix Composites (FGMMC) using vertical centrifugal casting technique and machining the manufactured specimen using Electric Discharge Machining (EDM) with varied level of operating parameters such as pulse current (Ip), pulse on time (Ton) and zones from the outer periphery of the specimen. The performance considered are surface roughness and overcut. Taguchi L9 orthogonal array table was designed to conduct the machining experiments. TOPSIS technique was used to find the optimum operation parameters through closeness coefficient values. The optimal setting operation parameters are pulse current 5A, pulse on time 75 μs, and zone from the outer periphery 30 mm. ANOVA revealed that the pulse on time is the most influencing operation parameters on the response continued by pulse current and zone from the outer periphery. The results showed that the mixed TOPSIS and ANOVA was the successful method to improve the machining operations.