采用电镀镍/铜中间层TLP扩散连接TC4钛合金

TLP diffusion bonding of TC4 titanium alloy with electrodeposited Ni/Cu interlayers

采用电镀镍/铜中间层实现了TC4钛合金瞬时液相扩散连接,采用配备有能谱探测器的扫描电子显微镜和X射线衍射仪对接头的微观组织进行分析,并结合Ti-Cu和Ti-Ni二元相图阐明了反应机制。结果表明,瞬时液相扩散连接接头的典型界面组织为TC4/α-Ti+Ti_(2)(Cu,Ni)/Ti_(3)Cu_(4)+TiCu+Ti_(2)(Cu,Ni)/α-Ti+Ti_(2)(Cu,Ni)/TC4。随着连接温度的升高,接头中央反应区Ti_(3)Cu_(4)相、Ti Cu相和高Al、V含量的Ti_(2)(Cu,Ni)相消失,而Ti_(2)(Cu,Ni)相宽度大大减小,同时条块状Ti_(2)(Cu,Ni)相开始呈现细小的羽毛状或枝晶状。当温度达到960℃时,接头组织基本一致,接头中元素实现充分均匀化。在此期间,接头室温抗拉强度和剪切强度均逐渐增大,在960℃时达到最大抗拉强度519 MPa和最大剪切强度195 MPa。

The TLP diffusion bonding of TC4 titanium alloy was achieved using electrodeposited Ni/Cu interlayers.The interfacial microstructure of the joint was analyzed by scanning electron microscopy equipped with energy disperse spectroscopy and X-ray diffractometer,and the reaction mechanism was illustrated by Ti-Cu and Ti-Ni binary phase diagram.The results show that the typical interfacial microstructure of the joint is TC4/α-Ti+Ti_(2)(Cu,Ni)/Ti_(3)Cu_(4)+TiCu+Ti_(2)(Cu,Ni)/α-Ti+Ti_(2)(Cu,Ni)/TC4,and Ni element exists in the form of solid solution.As the increase of the bonding temperature,Ti_(3)Cu_(4),Ti Cu and Ti_(2)(Cu,Ni) with high Al and V content in the central reaction zone disappear,whereas the width of Ti_(2)(Cu,Ni) phase decreases significantly.Simultaneously,The lumpy Ti_(2)(Cu,Ni) phase appears finely feathery or dendritic structure.When the temperature reaches 960℃,the microstructure is basically the same,and the elements in the joint are fully homogenized.In this process,the tensile strength and shear strength of the joints increase gradually,reaching the maximum values of 519 MPa and195 MPa at 960℃,respectively.