Interdiffusion between Ni Based Superalloy and Diffusion Barrier Coatings at 1423K
A diffusion couple study was carried out with Ni-based superalloy / γ’-Ni3Al with or without a Re-based alloy layer. The Re-based alloy containing Re, W, Cr, and Ni was formed on a second generation, single crystal Ni-based superalloy by using electroplating processes to form films of 70at%Re-Ni and Ni-20at%W, followed by Cr-pack cementation at 1573K for 36ks. The superalloy with or without the Re-based alloy layer was bonded to a γ’−Ni3Al alloy in vacuum. Diffusion couples were annealed in an evacuated quartz ampoule at 1423 K for 90 and 360ks. After the 360ks diffusion treatment the Re-based alloy remained sound and suppressed inward Al diffusion from the γ’-Ni3Al, it was further found that outward diffusion of alloying elements from the alloy substrate to the γ’-Ni3Al was also significantly reduced by the Re-based alloy layer.
Shigeji Taniguchi, Toshio Maruyama, Masayuki Yoshiba, Nobuo Otsuka and Yuuzou Kawahara
H. Matsumaru, S. Hayashi, T. Narita, "Interdiffusion between Ni Based Superalloy and Diffusion Barrier Coatings at 1423K", Materials Science Forum, Vols. 522-523, pp. 285-292, 2006