Microstructures and mechanical properties of Ti-6Al-3Nb-2Zr-Mo alloy fabricated by electron beam rapid manufacturing

The Chemical compositions, microstructure, mechanical properties, toughness of Ti6321 alloy made by electron beam rapid manufacturing (EBRM) were studied. The 1% of Al in the solder wire was burned during the manufacturing process, and no element segregation was found. The as-built microstructures exhibit large columnar grains, which grew epitaxially along the height direction of deposits through many deposition layers. The columnar grain is mainly composed of α lamellae. As a result, the anisotropic coefficient of tensile strength is 2. 6%. Dimple are observed on fractured tensile specimens in both X and Z directions. The impact toughness of X and Z direction is not less than 80J, and the anisotropic coefficient of toughness is 2.6%. The impact fracture is typical ductile fracture, which consists of a large number of dimples.