Formation of Nitrides and Carbides on Titanium Alloy Surface through EDM

Abstract

In this investigation, electrical discharge machining (EDM) was done with Cu-TaC powder metallurgy (PM) electrode and urea solution dielectric fluid. The main objective is to improve the surface wear property of Ti-6Al-4V alloy through the formation of hard ceramic compounds on its surface during EDM. The experiments were conducted with peak current, I p (3.5, 5.5 A) and pulse duration, t on (3.3, 5.3 µsec) as the machining variables. The outputs investigated are surface characteristics and micro-hardness. The formation of nitrides, carbides and oxides of tantalum and titanium on the EDMed surface was confirmed. The highest micro-hardness of 902.2 Hv was obtained with I p of 5.5 A and t on of 3.3 µsec.