Study on the diffusion barrier effect of WSi2 layer at the MoSi2/Nb-Ti-Si based alloy interface. (February 2020)

• Record Type: Journal Article
• Authors: Yue, Gao; Guo, Xiping; Qiao, Yanqiang
• Is Part Of: Corrosion science. Volume 163(2020)
• Publication Date: 2020-02
• Subjects: A. Intermetallics -- B. SEM -- C. High temperature corrosion -- C. Oxidation; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2019.108299
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: MoSi2 /WSi2 compound coating was prepared on the Nb-Ti-Si based alloy. WSi2 layer can slow down the growth rate of inner NbSi2 layer. The MoSi2 /WSi2 compound coating shows excellent protection for the substrate. WSi2 layer can suppress the interfacial diffusion and degradation of MoSi2 layer. Abstract: WSi2 layer was introduced at MoSi2 /Nb-Ti-Si based alloy interface to suppress the elemental diffusion. During coating formation process, inward diffusion of [Si] could be retarded and the growth rate of inner NbSi2 layer was slowed down consequently. At 1250 °C, the MoSi2 /WSi2 compound coating showed superior oxidation resistance relative to MoSi2 /NbSi2 compound coating in terms of thinner scale and less MoSi2 consumption. Parabolic rate constants of scales grew on these two coatings are 0.929 μm 2 h −1 and 4.782 μm 2 h -1, respectively. The improvement was resulted from the WSi2 layer, which acted as both a diffusion barrier and Si reservoir simultaneously.