钛/铜异种金属电弧焊焊接接头界面组织与力学性能

Microstructure and properties of dissimilar materials Ti/Cu welding joint by arc welding

为推动钛/铜异种金属焊接结构的广泛应用,利用常规的钨极氩弧焊进行了TA2纯钛和T2紫铜异种金属对接焊,通过扫描电镜、能谱仪、X射线衍射仪对所获得的钛/铜焊接接头微观组织进行了分析。结果表明:钛/铜异种金属焊接接头界面反应层生成了厚约50μm的金属间化合物,该金属间化合物层由钛侧条棒状金属间化合物CuTi、中间层块状和枝晶状金属间化合物Cu2Ti、沿着枝晶状化合物Cu2Ti边缘分布的化合物Cu4Ti3组成。合金元素Ti向焊缝金属中的溶解和扩散量极少,钛/铜焊接接头界面反应层化合物形成以液相扩散反应为主。拉伸试验表明焊接接头的抗拉强度达到了171 MPa,接头断裂于邻近钛母材侧的金属间化合物层,断口属典型的脆性解理断裂。

In order to promote the wide application of Ti/Cu dissimilar Metal welding structure,dissimilar metals of TA2 titanium and T2 copper were joined with butt joint by conventional argon tungsten-arc welding.The interfacial microstructures of the joints were analyzed by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffractometry(XRD).The results show that an intermetallic compound with a thickness of about 50μm forms in the interface reaction layer of Ti/Cu welding joint.The intermetallic compound layer is composed of CuTi,Cu2Ti and Cu4Ti3.The rod-like CuTi is near the titanium side,the massive and dendriticas Cu2Ti distribute in the intermediate region of the interfacial reaction,and Cu4Ti3 distributes along the edge of the dendrite compound Cu2Ti.The dissolution and diffusion of alloying element Ti to weld metal are very few,and the formation of interface reaction layer compound of Ti-Cu welding joint is dominated by liquid phase diffusion reaction.The tensile strength of the welding joint is up to 171 MPa,and the joint fractures in the intermetallic compound layer adjacent to the titanium base material,and the fracture is a typical brittle cleavage fracture.