Experimental Investigation and Optimization of Cryogenically Treated Titanium Grade-2 Alloy in Electrical Discharge Machining

Cryogenic treatment of work material is found to improve mechanical and thermal properties which gave the advantage of better machinability especially for difficult to machine materials such as titanium alloys. Titanium alloys are hard to machine because of its poor conductor of heat and high thermal coefficients. In order to improve the thermal conductivity titanium alloy was treated cryogenically. In this present study, the experimental investigation is performed with three dissimilar electrodes such as Graphite, Copper, and Zirconium di Boride coated with copper, from which the major output parameters such as electrode wear rate, material removal rate, and surface roughness are examined. In order to perform multi-objective optimization, by focusing on selecting parameters (peak current, voltage, cryogenically treated and non-treated work material, type of electrode) which could result in higher material removal rate, low electrode wear rate and low surface roughness, grey relational analysis was used in the present work. From the analysis it was observed that machining using non-cryogenically treated work material with graphite electrode gives promising result on peak current of 12 A and voltage of 45 V which satisfies the multi-objective criteria. This study reveals an effective way of machining titanium grade-2 alloy using EDM.