Structure and mechanical property of wedge linear friction welding joint of TC17 titanium alloy

In order to solve the difficulty of forging and processing of aviation long-shaped integral parts, the method of wedge linear friction welding is proposed for piecewise combined fabrication, TC17 titanium alloy specimens were welded by wedge linear friction welding, according to the V shaped joints, the forming mechanism, microstructure and mechanical properties of the joints were analyzed. Results showed that the metal flow law in the welding process is significantly different from the common linear friction welding joint. the high temperature plastic metal gradually flows to the bottom tip with the wedge moving, resulting in a wider tip weld and a narrower upper part, the amount of the metal deformation in the thermal mechanical affected zone (TMAZ) of the forging side is greater than that in the vibration side. There is a wide TMAZ at the tip of the wedge in the joint, there is a heat affected area in this range, the tensile strength and the high cycle fatigue strength of the joints are equal to that of the base metal, and the specimens are all broken at the base metal area.