通过改变激光在铝合金上聚焦时的光束偏移距离,对4 mm的Ti/Al异种合金进行焊接.焊后测试了不同参数条件下接头的力学性能,观察并分析了Ti/Al界面的微观组织形貌.试验结果表明:激光偏转角度为10°,光束偏移距离分别为1.1、1.2 mm时,Ti/Al界面处分别形成约30、10 μm的扩散层,此时断裂形式为脆断;光束偏移距离为1.3 mm时,Ti/Al界面处形成了约0.8 μm的扩散层,其主要成分为TiAl2、TiAl、Ti3Al金属间化合物,此时断裂形式为韧断,接头的抗拉强度最高,为192 MPa,达到铝合金母材强度的63%.%Ti/Al dissimilar alloys with thickness of 4 mm were welded by changing the offset distance of laser beam focusing on the aluminum.The mechanical properties of the joint under different processing parameters were investigated,and the microstructure and morphology of Ti/Al interface were observed and analyzed.The result indicated that when the deflection angle of laser head was 10° and the offset distance of laser beam were 1.1 mm and 1.2 mm respectively,the diffusion layers with thickness of 30 μm and 10 μm were obtained on Ti/Al interface respectively,and the fracture mode being brittle fracture.A diffusion layer with thickness of 0.8 μm could be obtained on Ti/Al interface when the offset distance of laser beam were 1.3 mm,and its principle component was TiAl2,TiAl and Ti3Al intermetallic compounds,the fracture mode being ductile fracture.Under this circumstance,the tensile strength reached its maximum value of 192 MPa,amounting to 63% of the tensile strength of the base metal.
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