Li, X.; Wei, Z.; Lv, W.; Zhang, L.; Liu, F.; Xie, X.; Lai, S.; Zhang, X. Structure and High-Temperature Oxidation Properties of an Al-Co-Y diffusion Coating prepared on TiAl-Nb alloy at a Low Temperature. Preprints2023, 2023090273. https://doi.org/10.20944/preprints202309.0273.v1
APA Style
Li, X., Wei, Z., Lv, W., Zhang, L., Liu, F., Xie, X., Lai, S., & Zhang, X. (2023). Structure and High-Temperature Oxidation Properties of an Al-Co-Y diffusion Coating prepared on TiAl-Nb alloy at a Low Temperature. Preprints. https://doi.org/10.20944/preprints202309.0273.v1
Chicago/Turabian Style
Li, X., Sheng Lai and Xuyi Zhang. 2023 "Structure and High-Temperature Oxidation Properties of an Al-Co-Y diffusion Coating prepared on TiAl-Nb alloy at a Low Temperature" Preprints. https://doi.org/10.20944/preprints202309.0273.v1
Abstract
Abstract: An Al-Co-Y diffusion coating was prepared on a TiAl alloy by pack cementation process at a low temperature range of 650-720 ℃. The influence of different activators and co-deposition temperatures on the coating’s microstructure and formation process, and high temperature oxida-tion performance was studied. The results showed that NaF was a more suitable activator for preparing the Al-Co-Y diffusion coating on TiAl alloy compared to NH4Cl and AlCl3. A more compact coating structure can be obtained when deposition was performed at 680 ℃ using NaF as the activator. The coating was mainly composed of a TiAl3 outer layer, a TiAl2 inner layer, and a thin Al-rich TiAl inter-diffusion layer. The growth of the coating exhibited a positive linear correlation between coating thickness increase and the square root of deposition time. The high-temperature oxidation tests showed that a dense scale mainly composed of Al2O3 and a small amount of TiO2 formed on the coating after oxidation at 950 ℃ for 100 h. The scale possessed excellent high-temperature oxidation resistance, with a parabolic rate constant of the oxidation weight gain approximately 4.9×10-3 mg2/cm4 h, which is lower than that of the TiAl substrate by about three orders of magnitude, and lower than that of the pure Al diffusion coating more than one order of magnitude.
Engineering, Metallurgy and Metallurgical Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
