Machining Optimization of Nano-structured Hardfaced Tool Insert in WEDM Using MOORA Method

Abstract

In recent years, nano-structured hardfacing alloy constituting fine carbides, borides and boro-carbides have become spearhead in cutting edge producing enterprises because of their prevalent properties like excellent hardness, toughness and wear resistance even at elevated temperatures. Nano-structured hardfacing alloy was produced using manual metal arc welding technique. This paper has focused on wire electrical discharge machining (WEDM) process identifies the influence of process parameters that affect the material removal rate, machining time and surface roughness while machining of nano-structured hardfacing alloy. The paramount process parameters have been employed during experiments such as discharge pulse time, discharge stop time, servo voltage, wire tension and wire feed rate. Experiments were designed using Taguchi’s L25 orthogonal array. Multi-objective optimization was performed using MOORA (multi-objective optimization on the basis of ratio analysis) method coupled with PCA (principal component analysis) to identify optimal process parameters. The outcome demonstrates that discharge pulse time (0.5 µs), discharge stop time (8 µs), servo voltage (35 V), wire tension (800 g) and wire feed rate (7 m/min) are the optimal process parameters using brass wire and for zinc coated brass wire that corresponds to discharge pulse time (0.5 µs), discharge stop time (8 µs), servo voltage (41 V), wire tension (500 g) and wire feed rate (7 m/min) respectively.