Microstructures and mechanical properties of Ti-6Al-3Nb-2Zr-1Mo alloy fabricated by CMT-wire arc additive manufacturing

The microstructure, mechanical properties and anisotropy of Ti-6Al-3Nb-2Zr-1Mo alloy made by CMT-Wire Arc additive manufacturing(CMT-WAAM) were studied. The as-built microstructures exhibit irregular polygons prior β and grain boundary α. This technology can refine the grains, and no columnar prior β grain morphology is observed. No martensite phase was discovered. The tensile strength in both directions have reached the standard requirements of the same level forging. No obvious texture is observed, and the anisotropy in tensile behavior is not obvious. There is no obvious texture and anisotropy in the manufactured structure. The ductility in transverse specimens was limited by the presence of lack-of-fusion porosity. The impact toughness of x and z direction is not less than 65 J. The impact fracture is typical ductile fracture,which consists of a large number of dimples.