5A02铝合金TG‒TLP焊接接头的组织及性能

Effect of Temperature Gradient on 5A02 Aluminum Alloy Welded by TG-TLP

目的研究5A02铝合金温度梯度瞬间液相扩散焊(TG‒TLP)焊接接头的组织及性能。方法采用TG‒TLP对5A02铝合金导管进行焊接,研究温度梯度对接头的组织和力学性能的影响,为探究5A02铝合金导管的TG‒TLP连接机理提供理论依据。结果水冷铜块离焊缝的距离d=15 mm,5A02铝合金TG‒TLP接头强度最高,达到90.7 MPa。随水冷铜块离焊缝的距离d的减少,接头处熔合线组织形貌由平直状到正弦状最后呈树枝状。当水冷铜块离焊缝的距离d大于15 mm时,熔合线组织形貌由平直状到正弦状,连接界面接触面积增大,接头强度提高;当水冷铜块离焊缝的距离d小于15 mm时,熔合线组织形貌由正弦状最后到树枝状,有大量的界面空隙产生,接头强度降低。结论焊接接头强度随水冷铜块离焊缝距离的减少呈先增加后减少的变化趋势。

Temperature gradient transient liquid diffusion welding(TG-TLP)was used to weld 5A02 aluminum alloy conduit.The effect of temperature gradient on the microstructure and mechanical properties of the joint was studied,which provided theo-retical basis for exploring the TG-TLP bonding mechanism of 5A02 aluminum alloy conduit.The results show that the welded joint strength increases first and then decreases with the decrease of the distance between the water-cooled copper block and the weld.When the distance between the water-cooled copper block and the weld is d=15 mm,the strength of the TG-TLP joint of 5A02 aluminum alloy is the highest,reaching 90.7 MPa.With the decrease of the distance d from the water-cooled copper block to the weld,the microstructure of the fusion line at the joint changes from straight to sinusoidal and finally to dendritic.When the dis-tance d from the water-cooled copper block to the weld is greater than 15 mm,the microstructure of the fusion line changes from straight to sinusoidal,the interface contact area increases,and the joint strength increases.When the distance d from the wa-ter-cooled copper block to the weld is less than 15 mm,the microstructure changes from sinusoidal to dendritic,and a large number of interfacial voids occur,and the joint strength decreases.