镍作中间层脉冲加压扩散连接钛合金与不锈钢

Impulse pressuring diffusion bonding of titanium alloy to stainless steel with nickel interlayer

采用纳米Ni粉、纳米Ni镀层、Ni箔作中间过渡层,对TA17近α型钛合金与0Cr18Ni9Ti不锈钢进行了脉冲加压扩散连接,接头抗拉强度分别达到了175,212,334 MPa。在金相显微镜下,对拉伸断口形貌进行了观察和分析;利用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射分析(XRD)测定了连接接头各区域内的微区成分和物相。结果表明,纳米Ni粉致密度不够高,纳米Ni镀层质量不够高,在很大程度上限制了接头强度的提高;Ni箔中间层的存在成功地阻止了Fe与Ti之间的互扩散,避免了形成脆而硬的Fe-Ti系金属间化合物。

Titanium alloy TA17 and austenitic stainless steel 0Cr18Ni9Ti were bonded by using impulse pressuring diffusion bonding(IPDB) with nano nickel particles,nano nickel plating and pure nickel foil as a interlayer,respectively,and the tensile strength of bonded joint was tested.The bonding strength of the joint bonded by using the three types of nickel interlayer metals has reached as high as 212 MPa,175 MPa and 334 MPa, respectively.The properties of the bonded joint using pure nickel foil are clearly better than the joints obtained by nano nickel particles and nano nickel plating. The fracture appearances were observed and analyzed by metallographic microscope.Element distribution and phase structures of each joint zone were analyzed by scanning electron microscope(SEM) and energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD).The results show that the density of the nano nickel particles interlayer is not high enough,the quality of the plating interlayer of nano nickel is not good enough which limited the increase of the joint strength,but Ni interlayer has successfully inhibited interdiffusion of Fe and Ti and avoided forming Fe-Ti series intermetallics.