Investigating Output Characteristics in Powder Mixed Electrical Discharge Machining of γ- TiAl Intermetallic

γ–TiAl intermetallic has outstanding properties such as high resistance against fatigue, oxidation, corrosion, creep, dynamic vibration and high working temperature. These intermetallics are applied in aerospace and automotive industry, turbojet engines and blade manufacturing. In this paper, powder mixed electrical discharge machining (PMEDM) of γ–TiAl intermetallic by means of different kinds of powders including Al, SiC, Gr, Cr and Fe is investigated to compare the output characteristics of the process such as surface roughness, tool wear rate, material removal rate and surface topography with each other. This is an experimental investigation, by means of die sinking EDM machine and a special tank for machining. The results indicate that, aluminum powder as the most appropriate kind of powder in the optimum particle concentration of 2 g/l, improves the surface roughness about 32% comparing with conventional EDM, decreases the tool wear rate about 19%, but decreases the material removal rate about 7.5% and also the Al powder leads to improving the machined surface topography and decreasing the surface defects and micro cracks.