Surface integrity and material transfer investigation of pure titanium for rough cut surface after wire electro discharge machining

Abstract

This article presents an experimental investigation of wire cut electro discharge machining of pure titanium. The marvelous characteristics of pure titanium such as its compatibility and noticeable physical, mechanical and biological performances have led to their increased application in various industries especially in seawater pipings, heat exchangers, implants, prosthesis, airframe and aircraft engine parts over the last 50 years. However, due to low thermal conductivity of titanium and their reactivity with cobalt in most tool materials, there are some difficulties in machining titanium and its alloys by conventional machining. On the other hand, unconventional machining processes especially wire cut electro discharge machining are more appropriate techniques for machining difficult-to-machine materials like pure titanium. This research work is mainly focused on microstructure analysis in terms of machining parameters such as pulse on time, pulse off time, peak current, spark gap using energy-dispersive X-ray, scanning electron microscope and X-ray diffraction techniques. The present results reveal that pulse on time and peak current significantly deteriorate the microstructure of machined samples, which produces the deeper, wider overlapping craters, pockmarks, globules of debris and micro-cracks. The microstructure analysis of rough cut surface was based upon the theory of electrical discharge phase and metallurgical physics.