Experimental and Computational Study of Interdiffusion for fcc Ni-Co-W Alloys

摘要

By means of the diffusion couple technique, electron probe micro-analyzer measurement and diffusion controlled transformation simulation, the interdiffusion behavior of ternary fcc Ni-Co-W alloys has been investigated. In the present work, the concentration profiles of fcc Ni-Co-W diffusion couples annealed at the temperatures of 1273, 1373 and 1523 K for the whole Ni-Co edge (i.e. W-poor) region of the fcc phase were measured. Based on the concentration profiles, the interdiffusion coefficients were deduced and used to assess the diffusion mobilities in conjunction with the thermodynamic description. The calculated diffusivities and experimental diffusion coefficients agree well. In addition, validation of the diffusion mobilities have been performed by further comparing the calculated concentration profiles and diffusion paths with the experiment data obtained in the present work.