Effects of Oxygen Content in the Argon Shielding Gas on Microstructure and Mechanical Properties of Laser Deposition Manufacturing TA15 titanium alloy

Abstract:

The TA15 titanium alloy specimens were prepared by laser deposition manufacturing. The effects of oxygen content in the argon shielding gas on microstructure, fracture and mechanical properties of laser deposition manufacturing TA15 titanium alloy have been investigated by optical microstructure (OM) and scanning electron microscopy (SEM). The results show that both as-deposited and annealed specimens microstructure are typically basket-weave microstructure without dramatic changes with the increasing of the oxygen content of the atmosphere. The tensile strength at room temperature of the annealed alloy is gradually on the rise while the ductility is decreasing. By considering both the ductility and strength properties, samples with the oxygen content at 0~5×10^-5 have the best comprehensive mechanical properties. Microhardness of the annealed samples is lower than that of the as-deposited, and they are gradually enhancing with the increasing of oxygen content. Room temperature tensile fracture mechanism changes from ductile fracture to semi-cleavage and semi-ductile fracture with the increasing of oxygen content.