Investigation on tensile fracture properties of TA15 specimen formed by selective electron beam melting

Abstract

TA15 titanium alloy has presented in broad application prospects for high strength properties. However, it is difficult to obtain the complicated structure of TA15 titanium alloy parts by traditional reduction processing. The selective electron beam melting(SEBM) forming technology better solves this problem. Tensile fracture properties are the important evaluation index of SEBM forming quality. In the paper the microstructure distribution and the influence on tensile properties were analyzed. The tensile fracture morphology and mechanism were discussed and the tensile properties of TA15 under different forming process parameters were obtained. It is found the microstructure is mainly composed of basketweave and duplex microstructure. The tensile fracture is dominated by cup-cone shaped morphology, and the tensile fracture mechanisms are microporous polymer fracture and cleavage fracture. Due to the existence of original β crystallites, there are a large number of micro holes in section. It is known speed function is the most significant parameter affecting the tensile fracture properties of SEBM for TA15. As the speed function is 30 and 36 respectively, line offset is 0.20 mm, the tensile strength and percentage reduction in area of the forming samples are 1042.28 MPa and 34.81%, reaching the maximum.