中文摘要：

采用真空扩散焊接的方法获得了93W／Ni／Ta扩散焊接接头。利用万能试验机测试焊接接头剪切强度，通过XRD，SEM，EDS对焊接接头的物相组成和显微结构进行了分析。结果表明，93W／Ni／Ta扩散焊接接头剪切强度随焊接温度和保温时间的增加而增加，最大值达到244MPa。焊接接头主要由Ni／Ta和93W／Ni界面组成，界面处金属间化合物分别为hcp—Ni3Ta，fcc—Ni3Ta，Ni2Ta和Ni4W。接头断裂发生在Ni／Ta界面处，表明Ni／Ta界面为接头的弱结合处。焊接接头界面的形成主要分为物理接触、固溶体形成、金属间化合物形成和金属间化合物长大4个阶段。

英文摘要：

The vacuum diffusion bonding was used to weld 93W to Ta using Ni as an interlayer. Universal testing machine was used to test the shear strength of the bonded joint. The microstructure of the bonded joints was investigated by XRD, SEM and EDS. The results show that the shear strength increases with the increasing of bonding temperature and holding time, and exhibits a maximum value of 244 MPa. The joint is composed of the Ni/Ta and Ni/93W interface. The phases of hcp-Ni3Ta, fcc-Ni3Ta, Ni2Ta and Ni4W are formed in the interfaces The fracture of the joint takes place in the Ni/Ta interface rather than the Ni/93W interface. The reaction process of the welding joints can be divided into the following stages： effective physical contact, solid solution forming, intermetallic reaction layer forming, and intermetallic layer growing.