An Investigation on the Surface Integrity of Grade 5 Titanium Alloy Proceeding the Wire Electro-Discharge Machining (WEDM) Process

Abstract

This paper presents the experimental work of the surface roughness, surface topography, elementary analysis and microhardness of wire electro-discharge (WEDM) machining of grade 5 titanium alloy (Ti-6Al-4V). Ti-6Al-4V has wide range of application in alloys due to its superior mechanical properties such as corrosion resistance, high tensile strength and toughness. Based on its great hardness value, conventional machining leads to high rates of tool wear, thus, WEDM is an alternative to manufacture Ti-6Al-4V, in which better surface characteristics can be produced. This work explores the surface integrity of Ti-6Al-4V alloy after WEDM in different input parameter. From the experimental work, good surface integrity can be achieved with low peak current. The scanning electron microscope (SEM) analysis depicted the appearance of craters, crack, recast layer and globule of debris on the machined surface. Within the chemical composition on the machined surface, titanium seizes the highest percentage as there is no alternation of the metallurgical structure of the parent material. The microhardness value gradually increases from the machined surface to the parent material of Ti-6Al-4V due to over-aging of the machined surface and the work hardening during the process.