Research on formation analysis of Al-Mg-Si alloy FSLW process in aerospace technology

Abstract

Regarding traditional fusion welding challenges, this research will illustrate the impact of the combined welding parameter for the friction stir lap welding (FSLW) process for two Al-Mg-Si Al-alloy plate joints. Firstly, the oxide film on the surface of the workpiece was polished, and the surface was cleaned with absolute ethyl alcohol. Secondly, the sheets were fixed on a particular fixture. The “FSW-3LM-4012” machine was used to employ the welding process. The stir tool rotated counter-clockwise, and the “welding direction” was parallel to the “rolling-direction” of the base material. The width of the overlapped area of the upper and lower sheets was 50 mm. Finally, the result was optimized by cross-sectional analysis, fracture path analysis, microhardness analysis, and surface morphology analysis. It is evident that under the optimal value (1597.4 rpm-173.7 mm/min-0.124 mm) of the three applied welding parameters (WP), the heat input is the smallest, the grain size in the weld zone is the finest, and the effect of fine-grain strengthening is most apparent. As a result, the microhardness is the best. The research has practical implications for the FSLW process in modern aerospace and automobile company.