Microstructure and Mechanical Properties of Ti-6Al-4V Produced by Selective Laser Sintering of Pre-alloyed Powders

Abstract

The purpose of this research is to investigate the microstructure and mechanical properties of Ti6Al4V pre-alloyed powders producing by direct metal laser sintering technique. Through this research, the direct fabrication of Ti6Al4V metal parts by selective laser sintering machine has been carried out using EOS GmbH M270 equipment. Employing intricate thermo-mechanical interaction between the laser beam and the metallic powders, the machine consolidates predefined cross sections and binds the particles together to form solid parts which correspond to CAD data.The geometrical feasibility of the parts, including process accuracy were statistically analysed by simple benchmark studies. The intricate correlation between powder materials and process parameters were thoroughly investigated via fractography, metallography and standard physical testing.It was found that, SLS technologies are capable of directly producing near to full density metal parts with good mechanical properties.Ti6Al4V produced by laser sintering has very fine α+ microstructure. This fine and stable microstructure demonstrated a high yield stress and UTS with low elongation at break. The fracture surface has a dimple features typical of a ductile structure. Dimensional analyses were performed on the customised benchmark showing process accuracy below 50 m. Designated heat treatments modified the microstructure which influences the mechanical behaviour of the parts.