钛/镍/不锈钢脉冲加压扩散连接接头组织及力学性能研究

Microstructure and mechanical properties of Ti/Ni/stainless steel joint by impulse pressuring diffusion bonding

为抑制钛/不锈钢脉冲加压扩散连接接头界面产物的过度生长,降低界面脆性相对接头性能的不利影响,选用Ni做中间层对Ti和不锈钢进行扩散连接实验。利用扫描电镜、能谱分析、万能拉伸试验和XRD对脉冲加压扩散连接钛/镍/不锈钢接头显微组织和力学性能进行研究。结果表明:在钛/镍界面生成了Ti2Ni、Ti Ni和Ti Ni3金属间化合物层,在镍/不锈钢界面生成了Ni-Fe固溶体;当连接时间为90 s时,接头强度达到最大值,为360 MPa;在拉伸载荷下,接头沿钛/镍界面Ti2Ni和Ti Ni层发生断裂;接头断口形貌为大量的解理条纹,说明接头呈脆性。

To restrain the overgrowth of interfacial products and to lower the adverse effects resulting from interface fragility,nickel(Ni)was chosen as interlayer to conduct impulse pressuring diffusion bonding experiments between titanium(Ti)and stainless steel(SS). The interfacial microstructure and mechanical properties of impulse pressuring diffusion bonded Ti/Ni/SS joint were investigated using scanning microscopy(SEM),energy dispersive spectrum(EDS),tensile test and XRD. It is demonstrated that Ti2 Ni,Ti Ni and Ti Ni3 are generated at the Ti/Ni interface,and Ni-Fe solid solution is formed at the Ni/SS interface. Maximum joint strength of 360 MPa is obtained when bonding for 90 s. Under tensile loading,the fracture of joint occurs along the Ti2 Ni and Ti Ni layer at the Ti/Ni interface. A large number of cleavage patterns are observed at the fracture surface,indicating that the joints are brittle in nature.