Analysis and Optimization of Wire Electro Discharge Machining Parameters of TiNi Shape Memory Alloy Using Taguchi Technique

Abstract

This paper focuses on the investigation of the effect of process parameters on the responses such as material removal rate and surface roughness of Ti_49.4Ni_50.6 shape memory alloy machined by WEDM using Taguchi technique to obtain optimum machining process parameters. Whenever conventional machining process gets drossy, it becomes inevitable to use nonconventional machining processes like Wire-Electro Discharge Machining (WEDM). Considering the development of mechanical industry, the demands for alloy materials having high hardness and toughness are increasing. Machine tool industry has also made exponential growth in its manufacturing capabilities but still, machine tools are not used to their fullest potential. This limitation is a result of the failure to run machine tools at their optimum operating conditions. A number of experiments were conducted using the L18 orthogonal array on Electronica WEDM. A combined technique using orthogonal array and analysis of variance was used to investigate the contribution and effects of a pulse on time, pulse off time, spark gape set voltage, wire feed and wire tension on the MRR and surface roughness. It is observed that pulse on time is the most significant parameter for MRR and surface roughness with a percentage contribution of 35.69% and 59.02% respectively. Along with this pulse off time was observed to be the next significant parameter for MRR with percentage contribution of 34.47%. Thereafter, optimal machining parameters were obtained by analysis of mean.

Keywords: Ti49.4Ni50.6 Shape Memory Alloy, Wire Electro-Discharge Machining, L18 Orthogonal Array, Material Removal Rate, Surface Roughness, Taguchi Method, Analysis of Variance, Analysis of Mean