A Review of Electrical Discharge Machining on Titanium based Alloy

Abstract

Titanium belongs to the family of super alloys it is known as the metal of future because it possess potential to be used in aerospace, automobile industries, biomedical parts; surgical tool, due to excellent properties like high specific strength, low thermal expansion, good corrosion resistant at elevated temperature, also in subsea oil and gas operations, good wear etc. one of the major problem which is faced by the manufacturers in manufacturing Titanium parts is that it is very tough to use conventional machining process. Therefore it will be best to use thermo electric processes for machining super alloys like Ti64, Ti6246 etc. EDM are developed for micro electrodes and micro-holes are actually used but most of them involve micro-EDM machining. In this work, the aim is to review the effect of machine parameters on Ti64 by varying parameters such as electric parameter and non-electric parameters on MRR, EWR, surface integrity, hardness, DVEE, surface topography, composition and problems related to flow of debris. The study reveals that MRR can be increased by adding 4.0 g/l fine suspended graphite particles (10 µm)in kerosene as dielectric fluid with 30% reduction in  breakdown voltage at the cost of higher discharge frequency which in turns increases MRR which is greater in case of B4C particles in de-ionized water as die-electric fluid. SEM shows more micro cracks on machined surface due to crater mechanism these micro holes leads to failure of the component at high pressure and temperature conditions particularly in case of plane engine blades.