Microstructures and Mechanical Properties of Ti6Al4V Parts Fabricated by EBM: Effects of Manufacturing Defects and Thermal Treatment Conditions

摘要

A clear understanding of the defects associated with Ti-6Al-4V manufactured with electron beam melting (EBM) is needed to ensure performance in critical applications in the medical and aerospace industries. In this work, the influence of different manufacturing defects on mechanical properties of EBM Ti-6Al-4V material in as built condition were evaluated. Additionally, conventional thermal treatments and hot isostatic pressing (HIP) cycles conducted on electron beam melted specimens and its influence on microstructural evolution and mechanical properties were analyzed. The microstructural characterization of the as-built and heat treated components was carried out using various microscopy techniques including optical and scanning electron microscopy (SEM/EBSD). The fracture surfaces were analysed using SEM and the fractography results were correlated with the mechanical properties. Based on the obtained results the effects of internal defects and heat treatments were discussed. With the right set of parameters, mechanical properties well above specifications for forged or casted samples were obtained.