Yttria partially stabilised zirconia as diffusion barrier between NiCrAlY and Ni-base single crystal Rene N5 superalloy

摘要

A 7-8 wt.% yttria partially stabilised zirconia (YSZ) layer was fabricated by electron beam physical vapour deposition as a diffusion barrier (DB) between NiCrAlY coating and Ni-base single crystal Rene N5 superalloy. Oxidation and interdiffusion behaviour of the coating system was investigated at 1100 degrees C. The YSZ interlayer, as an active DB, reacted with Al from superalloy substrate and NiCrAlY overlayer to form two continuous adherent alumina layers, which suppressed interdiffusion between substrate and overlayer effectively. The results indicated that the coating system with DB exhibited excellent oxidation resistance due to the inhibition of interdiffusion of alloying elements. (C) 2015 Elsevier Ltd. All rights reserved.