Zhao Yaowu, Qin Xueqian, Long Yuhong, Zhou Jia, Jiao Hui
Guangxi Key Laboratory of Manufacturing Systems and Advanced Manufacturing Technology, School of Mechanical & Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China.
Materials (Basel). 2023 Mar 23;16(7):2560. doi: 10.3390/ma16072560.
The welding of steel-aluminum dissimilar metals plays a vital role in promoting automobile lightweight. However, it is tricky to obtain good mechanical properties of steel-aluminum laser weldments. Based on the principle of preheating welding, the laser double-pass reciprocating welding method of steel-aluminum dissimilar metals was proposed. In the experiment, different weld spacing such as 0, 0.5, 1.0, 1.5, and 2.0 mm were set, and numerical calculations of the temperature field of the molten pool were carried out. The results show that the tensile strength of weldment depends on the mechanical properties of the second weld seam in the optimal welding parameters. Compared with other weld spacing, when the weld spacing is 1.5 mm, the preheating temperature, peak temperature, and pool width on the steel side of the second weld are lower. In contrast, the weld penetration's peak value and molten pool center's temperature reach the maximum on the aluminum side. The thickness of the steel/aluminum transition layer changed from 14 to 11 to 8 μm with increased weld spacing. Moreover, the fracture mode of the second weld is a ductile fracture. Furthermore, the average tensile strength can reach 76.84 MPa. The results show that appropriate weld spacing and preheating temperature can effectively improve the tensile strength of the welding joint.
钢铝异种金属的焊接在推动汽车轻量化方面起着至关重要的作用。然而，要获得具有良好力学性能的钢铝激光焊件并非易事。基于预热焊接原理，提出了钢铝异种金属激光双道往复焊接方法。在实验中，设置了0、0.5、1.0、1.5和2.0mm等不同的焊缝间距，并对熔池温度场进行了数值计算。结果表明，在最佳焊接参数下，焊件的抗拉强度取决于第二条焊缝的力学性能。与其他焊缝间距相比，当焊缝间距为1.5mm时，第二条焊缝钢侧的预热温度、峰值温度和熔池宽度较低。相反，铝侧焊缝熔深峰值和熔池中心温度达到最大值。随着焊缝间距增大，钢/铝过渡层厚度从14μm变为11μm再变为8μm。此外，第二条焊缝的断裂模式为韧性断裂。而且，平均抗拉强度可达76.84MPa。结果表明，合适的焊缝间距和预热温度能有效提高焊接接头的抗拉强度。
