Abstract:The linear friction welding behavior of TC17(α+β)/TC17(β) was investigated using several different processing conditions of frequency(20 to 50 Hz), amplitude (1 to 4 mm), friction pressure(32 to 96 MPa). The experimental research analyzed the influence of different welding parameters on the quality of LFWed joints, the microstructure of different regions of joints. The results showed that when the heat input is insufficient, a good welding joint can not be obtained. When other welding parameters remain unchanged, with the increase of single parameter, the heat input increases rapidly, the welding process reached a stable state, and the influence of parameters on the welding process and joint quality was small.?It was observed that phase transition and dynamic recrystallization were occurred in the weld region during the welding process, and finally formed a metastable β phase after weld; the equiaxed and lath α phase were elongated along the vibration direction, and the intergranular needle-like secondary α phase was completely dissolved in both sides of the thermo-mechanically affected zone because of undergoing thermal coupling.