钛与低碳钢的夹铜电阻点焊接头的特性

Characteristics of resistance spot welded joint between titanium and low carbon steel with an interlayer of copper

为改善接头性能,以100μm厚的铜箔为中间层对钛与低碳钢Q235进行电阻点焊。观察、分析了接头中各特征区域的微观结构,探讨了焊接电流、焊接时间和电极压力对接头熔核尺寸及抗剪载荷的影响。结果表明:以铜为中间层的钛与低碳钢点焊接头熔核内部与端部分别由Ti-Fe系和Cu-Ti系金属间化合物构成。接头的抗剪载荷随焊接电流、焊接时间及电极压力的增大而呈先增大后下降的变化趋势,接头最大抗剪载荷约为4.2 kN。接头的断裂方式主要呈界面撕裂破坏,熔核内部的Ti-Fe金属间化合物呈脆性断裂,端部的Cu-Ti化合物呈准韧性断裂。

In order to improve the joint properties,resistance spot welding of titanium and low carbon steel Q235 was carried out with 100μm thick copper foil as the interlayer.Microstructure of each characteristic region in the joint was observed and analyzed,and the effects of welding current,welding time and electrode pressure on nugget size and tensile shear load of the joint were studied.The results show that the inner and end of the nugget of the spot welded joint of titanium and low carbon steel with copper as interlayer are composed of Ti-Fe and Cu-Ti intermetallic compounds,respectively.With the increase of welding current,welding time and electrode force,the tensile shear load of the joint increases first and then decreases,and the maximum tensile shear load is about 4.2 kN.The fracture mode of the joint is mainly interfacial tearing failure,the Ti-Fe intermetallic compound in the nugget is brittle fracture,and the Cu-Ti compound in the end of the nugget is quasi ductile fracture.