Influence of Mo Content on Microstructure and Microhardness of Laser Solid Formed Ti-6Al-Mo System Alloys

The novel Ti-6Al-yMo (3≤y≤11) titanium alloys were deposited from blended Ti, Al and Mo powders using the laser solid forming (LSF) process and the microstructure and hardness of as-deposited layers were investigated. Results show that the volume fraction of the prior α colony decreases and the microstructure changes from widmanstätten structure to basketweave structure with the increase of Mo content. Meanwhile, the average size and aspect ratio of the prior α lath decrease and the volume fraction of the secondary α laths increases with the increase of Mo content. The microhardness of as-deposite layers was also measured, and it is found that the hardness of as-deposited Ti-6Al-yMo alloys increases predominantly linearly with the increase of the Mo content until 11 wt% Mo.