.2524 Sheet Friction Stir Welding Process

Currently, the riveting is the main connection technologies of aircraft skin. With the concept of green, energy saving, environmental protection becoming to the international consensus, the demand for aircraft lightweight becomes increasingly urgent. Friction stir welding technology has become the most important development trend of aircraft skin connection. Currently 2524 aluminum alloy has become the main material of aircraft skin. In this paper, we use friction stir welding method to study the 2524-T3 aluminum alloy sheet Welding technology and defects in nondestructive testing technology, which verifies the technological feasibility program for the friction stir welding applications in the aircraft skin connection technology.Based on the theory of friction stir welding heat generation, A three-dimensional heat transfer model of 2524-T3 aluminum alloy FSW has been established. The different welding stage and different position temperature distribution according to the different welding parameters effects on temperature field have been analyzed by ANSYS software. The simulation results are consistent with the test results, and according to this model optimize the start welding preheating time and pad material impact on the welding quality successfully, which verify the correctness of the model.We conducted a single-channel friction stir butt weld test on 1.8 mm thick 2524-T3 aluminum alloy sheet based on numerical analysis, and the mechanical properties and microstructure of the welding joint were analyzed. With the dynamic water and rolling technology a series of welding problems of aluminum sheet such as difficult to be formed, deformation, instability can be resolved creatively. For the characteristics of friction stir welding sheet, Focused the formation mechanism of the four defect type such as flash, lack of penetration, holes and grooves which appears in the process of friction stir welding, And put forward the corresponding non-destructive testing technology and developed a highly efficient ultrasonic welding method to control and eliminate defects. The results showed that when in the appropriate range of parameters the good joints with good superficial shaping quality and almost no deformation and no internal defects can be obtained. When at the rotating speed 2400r/min and the welding speed 150mm/min, the joint's average tensile strength reaches 409.5MPa, which is 92.9% of base metal. Finally, we succeeded in welding a 1.2m long boards based on the optimization of the welding technology and NDT resultsExperimental Verification of the feasibility of the friction stir welding technology in the application of commercial aircraft skin connecting and acceptanced by the parties for funding the project. The results of friction stir welding in aerospace manufacturing engineering will play an important role in promoting and reference value.