| CAO Jun,LIU Wei,ZHU Peng-fei,SUN Tie-long,LI Ji-wen,PAN Kun-ming,WEI Shi-zhong.Preparation of MoSi2 High Temperature Oxidation Resistant Coating by Slurry Infiltration Method[J],48(1):69-76 |
| Preparation of MoSi2 High Temperature Oxidation Resistant Coating by Slurry Infiltration Method |
| Received:November 02, 2018 Revised:January 20, 2019 |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2019.01.010 |
| KeyWord:slurry infiltration method molybdenum matrix MoSi2 antioxidant coating NaF activator heat treatment |
| Author | Institution |
| CAO Jun |
a.School of Materials Science and Engineering, b.Henan Key Laboratory of High-temperature Structural and Functional Materials, Henan University of Science and Technology, Luoyang , China |
| LIU Wei |
a.School of Materials Science and Engineering, b.Henan Key Laboratory of High-temperature Structural and Functional Materials, Henan University of Science and Technology, Luoyang , China |
| ZHU Peng-fei |
a.School of Materials Science and Engineering, b.Henan Key Laboratory of High-temperature Structural and Functional Materials, Henan University of Science and Technology, Luoyang , China |
| SUN Tie-long |
a.School of Materials Science and Engineering, b.Henan Key Laboratory of High-temperature Structural and Functional Materials, Henan University of Science and Technology, Luoyang , China |
| LI Ji-wen |
a.School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang , China |
| PAN Kun-ming |
b.Henan Key Laboratory of High-temperature Structural and Functional Materials, Henan University of Science and Technology, Luoyang , China |
| WEI Shi-zhong |
b.Henan Key Laboratory of High-temperature Structural and Functional Materials, Henan University of Science and Technology, Luoyang , China |
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| Abstract: |
| The work aims to develop a novel process for preparing MoSi2 high temperature oxidation resistant coating on the surface of molybdenum substrate. The MoSi2 coating was synthesized on the surface of molybdenum substrate subtly by slurry infiltration method. The phases of the coating, including the main layer and transition layer, were analyzed and determined by X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The morphology of microstructure on surface and cross-section of the coating was observed by scanning electron microscopy (SEM). Model of slurry infiltration process was established to illustrate the formation mechanism of the silicide. The effects of process parameters, such as slurry coating thickness, activator (NaF) content, temperature and duration of heat treatment, on the thickness of silicide coating were investigated in detail. Bilayer silicide coating was prepared on the surface of the molybdenum substrate by slurry infiltration technology. The outer layer was a polygonal prismatic MoSi2, while the inner layer was a uniform and dense glassy Mo5Si3. Thinner slurry led to thicker inner layer (Mo5Si3) and thinner outer layer (MoSi2). The coating thickness was linearly correlated with the content of activator (NaF, 0~20wt%), and it was almost constant when the content of NaF was above 20wt%. The coating formation was effected significantly when the heat treatment temperature was around the phase transformation point of activator NaF and infiltration agent Si. The total thickness of the coating grew with longer heat treatment duration, but the coating formation rate had an inverted parabolic relationship with extended duration. The dense MoSi2 oxidation resistant coating can be synthesized on the surface of molybdenum by slurry infiltration technology at a relatively low heat treatment temperature (800~1400 ℃) in a relatively short heat treatment time (1~7 h). The total thickness of the coating can be increased by increasing heat treatment temperature and extending the heating duration. |
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