Oxidation and interdiffusion behavior of a germanium-modified silicide coating on an Nb–Si-based alloy
来源期刊：International Journal of Minerals Metallurgy and Materials2017年第3期
论文作者：Jin-long Li Wan Wang Chun-gen Zhou
文章页码：289 - 296
摘 要：To investigate the interdiffusion behavior of Ge-modified silicide coatings on an Nb–Si-based alloy substrate,the coating was oxidized at 1250°C for 5,10,20,50,or 100 h.The interfacial diffusion between the（Nb,X）（Si,Ge）2（X = Ti,Cr,Hf） coating and the Nb–Si based alloy was also examined.The transitional layer is composed of（Ti,Nb）5（Si,Ge）4 and a small amount of（Nb,X）5（Si,Ge）3.With increasing oxidation time,the thickness of the transitional layer increases because of the diffusion of Si from the outer layer to the substrate,which obeys a parabolic rate law.The parabolic growth rate constant of the transitional layer under oxidation conditions is 2.018 μm×h-1/2.Moreover,the interdiffusion coefficients of Si in the transitional layer were determined from the interdiffusion fluxes calculated directly from experimental concentration profiles.
Jin-long Li，Wan Wang，Chun-gen Zhou
Department of Materials Science and Engineering,Beihang University
摘 要：To investigate the interdiffusion behavior of Ge-modified silicide coatings on an Nb–Si-based alloy substrate,the coating was oxidized at 1250°C for 5,10,20,50,or 100 h.The interfacial diffusion between the（Nb,X）（Si,Ge）2（X = Ti,Cr,Hf） coating and the Nb–Si based alloy was also examined.The transitional layer is composed of（Ti,Nb）5（Si,Ge）4 and a small amount of（Nb,X）5（Si,Ge）3.With increasing oxidation time,the thickness of the transitional layer increases because of the diffusion of Si from the outer layer to the substrate,which obeys a parabolic rate law.The parabolic growth rate constant of the transitional layer under oxidation conditions is 2.018 μm×h-1/2.Moreover,the interdiffusion coefficients of Si in the transitional layer were determined from the interdiffusion fluxes calculated directly from experimental concentration profiles.
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