Experimental investigations and parametric optimization of WEDM on Incoloy 800, titanium alloy and AISI D3 tool steel

Abstract

Technologically advanced industries of the modern world such as space research, missile, automobile, nuclear, medical, mould tools and die making industry demand use of complex and intricately shaped components made from exotic alloys and high strength and temperature resistive materials. Over the years, the Wire Electrical Discharging Machining (WEDM) process has been acclaimed as a competitive and economical nontraditional machining process to produce complex and intricate shapes of components for various industries. Further, the development of newer and more exotic materials with different thermal properties or advanced materials such as Incoloy 800, Titanium alloy and AISI D3 tool steel have challenged the viability of the WEDM process for future manufacturing environment. Optimization techniques are required to identify the combination of parameters for achieving required cutting performance in WEDM process. Grey relational analysis combined with Taguchi method was applied to determine the optimum machining parameters for the WEDM process. Analysis of variance was used to find out the significant factors affecting the machining performance such as material removal rate, surface roughness and Kerf width. The surfaces machined by WEDM were examined using Scanning Electron Microscope to study the surface integrity and features. The study reveals the elimination of surface defects such as large pockmarks, cracks, craters and recast layer.The regression statistics proved that the mathematical models developed, have a high precision and they can be used to predict the levels of material removal rate, surface roughness and kerf width with a 95% confidence level. The mathematical model has been subsequently validated for the selected machining parameters, by examining the deviation between experimental and predicted values. The analysis has shown that deviation is well within the acceptable limits for the techniques employed.