Effect of yttrium on diffusion layer of Ni-Al-Mo-B alloy IC6 during high temperature oxidation process

Abstract

One of the critical requirements for a protective oxide scale on an alloy substrate to provide high temperature environmental resistance is that the scale should be adherent to the substrate. A directionally solidified (DS) alloy IC6 has been recently developed as a high-temperature structural material used for advanced jet-engine blades and vanes operating in the temperature range of 1,050-1,150 C. Its high temperature oxidation resistance is substantially improved by adding proper amounts of yttrium, which is attributed to several beneficial roles played by yttrium. One of the beneficial effects is that yttrium can inhibit the transportation of cations and hence decrease the increasing rate of the depth of the diffusion layer formed during high temperature oxidation process. The purpose of this paper is to investigate the effect of yttrium on the diffusion layer.