激光技术, 2023, 47 (2): 147, 网络出版: 2023-04-12  

不等厚铝/钢激光焊接接头组织与性能研究

Study on microstructure and properties of laser welded joints of aluminum/steel with different thickness
作者单位
长春理工大学 机电工程学院, 长春 130022
摘要
为了改善铝/钢连接性能, 采用激光技术通过调整工艺参数获得了拉伸强度达到铝母材40%的不等厚铝/钢对焊接头, 并对接头焊缝组织、界面化合物、力学性能展开了分析。结果表明, 焊接速率为1.8 m/min、激光向钢侧偏置0.3 mm、离焦量为0 mm、激光功率为3.0 kW时, 接头抗拉强度达到38 MPa; 保持其它焊接参数不变, 离焦量为-2 mm时, 接头抗拉强度进一步提升至57.7 MPa, 焊缝截面形状由酒杯状变为束腰状, 熔合线更加整齐, 附近裂纹、气孔缺陷明显减少; 焊缝界面区域物相衍射与能谱分析表明, 沿熔合线垂直方向生长的化合物为脆韧程度不尽相同的FeAl、FeAl3、Fe2Al5和Fe2CrAl、Fe3Al; 接头整体拉伸断裂模式为脆性断裂, 断口表面部分位置连接强度较好, 呈凹陷状, 检测发现Fe3Al。此研究结果在提升车身铝/钢连接处性能、车身减重以及节能减排方面具有重要现实意义。
Abstract
In order to improve the performance of aluminum/steel connection, an unequal thickness aluminum/steel pair welding head whose tensile strength is 40% of that of the aluminum alloy base metal was obtained using the laser technology by adjusting the process parameters. The joint weld structure, interface compounds, and mechanical properties were analyzed. The results show that the welding speed is 1.8 m/min, the laser is biased to the steel side by 0.3 mm, the defocusing amount is 0 mm, the laser power is 3.0 kW, and the tensile strength of the joint reaches 38 MPa, respectively. With the other welding parameters unchanged, when the defocus amount is -2 mm, the tensile strength of the joint is further increased to 57.7 MPa, the shape of the weld section changes from wine cup shape to corset waist, the fusion line is more neat, and the cracks and porosity defects near it are significantly reduced. Phase diffraction and energy dispersive spectrometer in the interface area of the weld showed that the compounds grown vertically along the fusion line were FeAl, FeAl3, Fe2Al5 and Fe2CrAl and Fe3Al with different degrees of brittleness. The overall tensile fracture mode of the joint is brittle fracture, the connection strength at some positions on the fracture surface is good, showing a concave shape, and Fe3Al is found through inspection Fe3Al. The results of this study are improving the performance of aluminum/steel joints in the bodywork, weight reduction and energy saving and emission reduction are of great practical significance.
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方正帅, 刘佳明, 黄根哲, 张宏, 刘凤德. 不等厚铝/钢激光焊接接头组织与性能研究[J]. 激光技术, 2023, 47(2): 147. FANG Zhengshuai, LIU Jiaming, HUANG Genzhe, ZHANG Hong, LIU Fengde. Study on microstructure and properties of laser welded joints of aluminum/steel with different thickness[J]. Laser Technology, 2023, 47(2): 147.

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