The effects of combinations of dissimilar aluminum alloys during Friction stir welding (FSW) on the process response and resultant joint properties are experimentally investigated using two dissimilar automotive structural aluminum alloys. Depending on the materials on the advancing and retreating sides of the tool travel direction during FSW, four different material combinations are considered. FSW joints without macroscopic defects are successfully fabricated for the four different material combinations. The optical microscopy results show that the macroscopic material mixing behaviors of the two dissimilar material combinations during FSW are somewhat different from each other, even though the process responses during joining are not much different. The results of the quasi-static tensile tests and EBSD analysis demonstrate that the mechanical behaviors and orientation changes of the joint during tensile deformation are affected by the material locations with respect to the tool travel direction during FSW.
相似文献The automotive industry has a target goal to improve fuel consumption due to restricted exhaust gas regulation. For this reason, the applicability of lightweight material, Al alloys, Mg alloys is also being expanded. In this concept, high strength steel, DP590 and light alloy, AL5052 are joined in the right place of the car body. However, it is difficult to join to steel and aluminum by conventional fusion welding. Generally, in respect to dissimilar metal joining by fusion welding, intermetallic compound layer is formed at the joint interface, hot cracking is generated. In this study, the effect of the current waveform on the mechanical characteristics and microstructure in Delta spot welding process of dissimilar metal was investigated. As results, Intermetallic compound (IMC) layer was reduced from 2.355 μm to 1.09 μm by using Delta spot welding process; also the welding current range improved by 50% in the delta spot welding, higher than in the inverter resistance welding. To conclude, the delta spot welding process adopting the process tapes contributes to improving the welding quality for dissimilar metals (Al5052 and DP590) due to a decrease in IMC layer.
相似文献
In consideration of uncertainties of material characteristics and its welding and forming process, an interval strain energy density method for predicting fatigue life of dissimilar lightweight metal welded joints was presented in this paper. Firstly, the mechanical performance parameters and fatigue properties of welded joints with parental material aluminum alloy 5083H111 and 5754 were obtained by experimental work. Based on the interval number approach, the interval relationship between the elastic and plastic strain energy density and fatigue life was constructed, including lower and upper interval bounds. Then, a finite element model of the dissimilar lightweight metal cross welded joint was generated to calculate the stress-strain response curve under cyclic loadings through the non-linear finite element analysis. The predicted lifetime and failure location for the cross welded joint based on the interval strain energy density method agreed well with the tested results.
相似文献