Track: Manufacturing

Abstract

The family of the gamma titanium aluminide alloys are of high importance due to their lower density and higher strength as compared to their competitor alloys such as Ti6Al4V in the automobile and aerospace applications. The current paper reports on the electron beam melting (EBM) and turning of the gamma titanium aluminide alloy (γ-TiAl). The γ-TiAl cylindrical parts are fabricated by using the ARCAM electron beam melting machine. After fabrication, the γ-TiAl parts are characterized by checking their surface morphology, microstructure, hardness, and surface roughness. All these measured characteristics show the acceptable levels for various applications except the surface roughness. The key limitation of the γ-TiAl parts fabricated from the electron beam melting process is their extremely poor surface roughness which is found to be as high as Sa = 34.9 µm. The surface roughness of the 3D printed γ-TiAl parts is further improved by employing the turning process by using two different tungsten carbide inserts radius (0.4 mm and 0.8 mm), and wide range of machining parameters including the cutting speed, feed rate, depth of cut and coolant flow rate. It has been attempted to find the optimized machining conditions to minimize the surface roughness and the cutting forces during the finishing process.