Diffusion behavior of W in the WCu/Ni interface

In order to clarify the W diffusion behavior at the WCu/Ni interface, a WCu/Ni diffusion couple was prepared, and the phase structure and constituents of the diffusion layer were characterized by a scanning electron microscopy and transmission electron microscopy. Based on the experimental data, the interdiffusion coefficient was calculated. The diffusion behavior was also verified by the simulation according to the first principle method. The results show that a diffusion layer with the thickness of 1 μm, which is composed of Cu rich solid solution and W rich solid solution, is formed on the surface of W particles. The interdiffusion coefficient of W in the transitional layer is 3.381 × 10−15 cm2/s, which is much larger than that of W in Ni. This is in good agreement with the simulation result.