Microstructure and Performance of Mo Surface Alloyed Ti6Al4V Gear

Double glow plasma surface alloying technology was used to prepare a molybdenum modified layer on the surface of TC4 alloy gears. The microstructure and hardness of the modified layers were analyzed. Running-in tests for gear pairs between different gears were carried out. The results show that the Mo modified layer of 18 μm in thickness consisted of a deposition layer and a diffusion zone, and formed metallurgical bond with the substrate. The hardness of the modified layer showed a gradual decrease with depth from the surface to substrate, and obtained a maximum value of 970 HK. The wear-resistance of the Mo-alloyed TC4 gears increased by 390% when running with 40Cr gear.