TC4钛合金不同焊接方法焊接性及接头性能分析

为了研究TC4钛合金在不同焊接方法条件下的焊接性及接头性能，对TC4钛合金分别进行了氩弧焊、冷焊、激光焊、电子束焊以及电阻点焊试验，并对接头的强度、硬度、塑性、韧性、金相组织等进行了对比分析。试验结果显示，采用TA18焊丝，氩弧焊接头强度平均值为982.5 MPa，伸长率为7.5%，强度和塑性匹配良好；冷焊接头强度平均值974.5 MPa，焊缝区硬度低于热影响区，热影响区宽度0.7~1.0 mm，焊接变形改善明显；激光焊接头强度平均值956.5 MPa，伸长率达母材水平；电子束焊接头强度高于母材，塑性低于母材，热处理后接头强度升高，焊缝区存在金相组织的梯度分布；电阻点焊接头的熔核直径和抗剪力随焊接参数增大逐渐增大。研究表明，TC4 钛合金具有良好的焊接性，在弧焊、束焊和电阻焊工艺下，焊接性良好，焊接接头金相组织合理，强度、塑性等 力学性能指标匹配良好。

Analysis of Weldability and Joint Properties of TC4 Titanium Alloy with Different Welding Methods

In order to study the weldability and joint performance of TC4 titanium alloy under different welding methods，argon arc welding，cold welding，laser welding， electron beam welding and electric resistance spot welding were carried out on TC4 titanium alloy，and the strength， hardness，plasticity，toughness and metallographic structure of the joint were compared and analyzed. The test results show that TC4 titanium alloy adopts TA18 welding wire，the average strength of argon arc welding joint is 982.5 MPa， the elongation is 7.5%，the strength and plasticity match well. The average strength of cold welding joint is 974.5 MPa，the hardness of weld area is lower than that of the heat affected zone，the width of heat affected zone is 0.7~1.0 mm，and the welding deformation is significantly improved. The average strength of laser welded joint is 956.5 MPa，and the elongation reaches the level of base metal. The strength of the electron beam joint is higher than that of the base metal，and the plasticity is lower than that of the base metal. The strength of the joint increases after heat treatment. There is a gradient distribution of metallographic structure in the weld area. With the increase of welding parameters，nugget diameter and shear resistance of resistance spot welding joint gradually increase. The research shows that TC4 titanium alloy has good weldability. Under the processes of arc welding，beam welding and resistance welding，the weldability is good，the metallographic structure of the welded joint is reasonable，and the mechanical properties such as strength and plasticity match well.