Effects of Solid Solution Plus Aging Treatment on Microstructure and Properties of Ti600/TC18 Alloy Joint by Inertia Friction Welding

Ti600/TC18 alloy heterogeneous alloy joints were prepared by inertia friction welding, and then the microstructure, mechanical properties and corrosion resistance of the joints were investigated while Ti600/TC18 alloy joints were undergone different solution（double annealing） plus aging treatments. The results show that the microstructure of Ti600/TC18 joints after heat treatment are composed of α’ and β phases, and the aging temperature mainly affects the precipitation mode of sub-stable phase β decomposition. With the increase of aging temperature, the tensile strength at room temperature is increased firstly and then decreased, the tensile strength at high temperature is decreased gradually, but the plasticity has no obvious change. When the high temperature of the double annealing is 880 ℃, the low temperature is 700 ℃ and the aging temperature is 610 ℃, the secondary α_S phase is coarse, straight and has obvious direction in the weld. The strength and toughness matching of Ti600/TC18 joint is better, and the Ti600/TC18 joint also shows better corrosion resistance in the 3.5 wt% NaCl solution.