Effect of pulsed electron beam irradiation on microstructure of TiC/Ti6Al4V composites fabricated by laser metal deposition

Abstract

Effect of pulsed electron beam irradiation on microstructure and phase composition of TiC/Ti-6Al-4V composite fabricated by laser metal deposition was investigated by X-ray and EBSD analysis, SEM and optical microscopy. The microstructure of the as-built TiC/Ti-6Al-4V composite consists of the equiaxed prior β grains with α-Ti lamellae with different orientations within them. TiC particles are located along the boundaries of the prior β grains. Pulsed electron beam irradiation leads to the refining of both the α-Ti lamellae and TiC particles and their more uniform distribution in the melted surface layer. The latter leads to an increase of the modified surface layer microhardness.