J. Mater. Sci. Technol. ›› 2020, Vol. 54: 171-180.DOI: 10.1016/j.jmst.2020.02.005

• Research Article • Previous Articles     Next Articles

Effect of Ni content in Cu1-xNix coating on microstructure evolution and mechanical properties of W/Mo joint via low-temperature diffusion bonding

Mei Raoa, Guoqiang Luoa,*(), Jian Zhanga, Yiyu Wangb, Qiang Shena, Lianmeng Zhanga   

  1. a State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China
    b Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831-6064, USA
  • Received:2019-07-18 Revised:2019-11-12 Accepted:2019-11-21 Published:2020-10-01 Online:2020-10-21
  • Contact: Guoqiang Luo

Abstract:

The 93W and Mo1 refractory metals were bonded with different Cu1-xNix coating interlayers of various Ni content using plasma-activated sintering at 700?°C. The effects of the Ni content in the Cu1-xNix coating interlayer on the interfacial microstructure evolution and mechanical properties of the W/Mo joints were studied. The maximum average shear strength of the W/Mo joint was 316.5?MPa when the Ni content of the Cu1-xNix coating interlayer was 25 %. When the Ni content of the Cu1-xNix coating interlayer was below 50 %, the atomic diffusion at the W/Mo joint interface was adequate without the formation of intermetallic compounds, as demonstrated by the High Resolution Transmission Electron Microscope analyses of the joints. The presence of Ni in Cu1-xNix promoted diffusion bonding at the interface, which contributed to the high mechanical properties of the W/Mo joint. With an increase in the Ni content of the Cu1-xNix coating interlayer, the MoNi intermetallic compound (IMC) nucleated and grew at the Cu1-xNix coating/Mo1 interface. When the Ni content of the Cu1-xNix coating interlayer was above 50 %, the generation of a brittle MoNi IMC weakened the shear strength of the W/Mo joint dramatically.

Key words: Refractory metal, Cu1-xNix coating interlayer Solid solution, MoNi IMC, Microstructure, Shear strength