Microstructure and high temperature oxidation resistance of Si–Y co-deposition coatings prepared on TiAl alloy by pack cementation process
Autor: | Yong-quan Li, Xiang-qing Wu, Fa-qin Xie |
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Rok vydání: | 2015 |
Předmět: |
Materials science
Alloy Metallurgy Metals and Alloys engineering.material Geotechnical Engineering and Engineering Geology Condensed Matter Physics Microstructure chemistry.chemical_compound Chemical engineering chemistry Coating Cementation process Phase (matter) Silicide Materials Chemistry engineering Layer (electronics) Order of magnitude |
Zdroj: | Transactions of Nonferrous Metals Society of China. 25:803-810 |
ISSN: | 1003-6326 |
DOI: | 10.1016/s1003-6326(15)63666-4 |
Popis: | In order to improve the high temperature oxidation resistance of TiAl alloy, Y modified silicide coatings were prepared by pack cementation process at 1030, 1080 and 1130 °C, respectively, for 5 h. The microstructures, phase constitutions and oxidation behavior of these coatings were studied. The results show that the coating prepared by co-depositing Si–Y at 1080 °C for 5 h has a multiple layer structure: a superficial zone consisting of Al-rich (Ti,Nb) 5 Si 4 and (Ti,Nb) 5 Si 3 , an out layer consisting of (Ti,Nb)Si 2 , a middle layer consisting of (Ti,Nb) 5 Si 4 and (Ti,Nb) 5 Si 3 , and a γ-TiAl inner layer. Co-deposition temperature imposes strong influences on the coating structure. The coating prepared by Si–Y co-depositing at 1080 °C for 5 h shows relatively good oxidation resistance at 1000 °C in air, and the oxidation rate constant of the coating is about two orders of magnitude lower than that of the bare TiAl alloy. |
Databáze: | OpenAIRE |
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