Rafting of γ'Phase and Diffusion of γ'Forming Elements in Single Crystal for DD402/FGH95 of Diffusion Couple

Regularities of interdiffusion of Al, Ti and Ta for DD402/FGH95 couple during HIP at different temperatures were studied. The up-hill diffusion flux of Al and Ta in single crystal DD402 was found. As a result, a rich zone of γ'phase forming elements and rafted γ'phase were developed in single crystal DD402 close to the bonded interface. The diffusion fluxes and diffusion depths of Al and Ta were calculated. The calculated results were corresponding to those the experiments.