| XIAO Lai-rong,GUO Yi,CAI Zhen-yang,ZHAO Xiao-jun,OUYang Hao,ZHANG Bei,PIAO Sheng-ming,LIU Jian-fei.Fabrication and Structure Properties of Si-Cr-Ti-SiC-MnO2 Coatings on Molybdenum Alloy[J],46(9):66-72 |
| Fabrication and Structure Properties of Si-Cr-Ti-SiC-MnO2 Coatings on Molybdenum Alloy |
| Received:April 19, 2017 Revised:September 20, 2017 |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2017.09.011 |
| KeyWord:molybdenum alloy silicide coating high emissivity coating high temperature oxidation resistance slurry sintering method MoSi2 Si-Cr-Ti |
| Author | Institution |
| XIAO Lai-rong |
a. School of Material Science and Engineering, b. The Key Laboratory of Non-ferrous Metals, Materials Science and Engineering, Ministry of Education, Central South University, Changsha , China |
| GUO Yi |
a. School of Material Science and Engineering, b. The Key Laboratory of Non-ferrous Metals, Materials Science and Engineering, Ministry of Education, Central South University, Changsha , China |
| CAI Zhen-yang |
a. School of Material Science and Engineering, b. The Key Laboratory of Non-ferrous Metals, Materials Science and Engineering, Ministry of Education, Central South University, Changsha , China |
| ZHAO Xiao-jun |
a. School of Material Science and Engineering, b. The Key Laboratory of Non-ferrous Metals, Materials Science and Engineering, Ministry of Education, Central South University, Changsha , China |
| OUYang Hao |
a. School of Material Science and Engineering, Changsha , China |
| ZHANG Bei |
a. School of Material Science and Engineering, Changsha , China |
| PIAO Sheng-ming |
a. School of Material Science and Engineering, Changsha , China |
| LIU Jian-fei |
a. School of Material Science and Engineering, Changsha , China |
|
| Hits: |
| Download times: |
| Abstract: |
| The work aims to improve infrared emissivity property and high temperature oxidation resistance of molybdenum alloy surface. Uniform suspension slurry was obtained after the slurry made of 40wt% Si, 20wt% Cr, 5wt% Ti, 5wt% SiC and 30wt% MnO2 powders as well as ethyl alcohol and bonder in proportion were milled with high energy ball for 6 h. Then the slurry was dip coated on the pretreated molybdenum alloy surface. Finally, the silicide coatings were synthesized at 1450 ℃ in vacuum atmosphere for 0.5 h and furnace-cooled down to room temperature. Oxidation resistance and infrared radiation properties of the silicide coatings were evaluated by performing high-temperature static oxidation test 1550 ℃ and high-temperature particle slice infrared spectroscopy integrated experimental system. Morphology and organizational structure of the unoxidized and oxidized coatings were analyzed by using SEM, EDS, and XRD. Normal infrared emissivity of the Si-Cr-Ti-SiC-MnO2 coating at 700 ℃ and 900 ℃ was 0.85 and 0.88, respectively. Static oxidization resistance life at 1550 ℃ in aerobic environment was 7 h. The original coating exhibited a four-layer composite gradient structure consisting of SiO2+Mn3O4+M5Si3, M5Si3+MoSi2+SiC+Mn3O4, MoSi2 layer and Mo5Si3 diffusion layer (outside-in). After oxidation at 1550 ℃ for 4 h, composition of the four-layer structure changed into SiO2+(Cr,Ti)5Si3+MnCr2O4+Mn3O4 layer, M5Si3+SiC+MnCr2O4+Mn3O4 layer, MSi2 layer and M5Si3 diffusion layer (outside-in). During the high-temperature oxidation process, the MSi2 high silicide layer gradually transformed into M5Si3 low silicide layer, and a dense SiO2 glass film containing MnCr2O4 spinel phase and composite silicide took shape on the coatings. The Si-Cr-Ti-SiC-MnO2 coating can effectively improve the infrared emissivity performance and high temperature oxidation resistance of the molybdenum alloy substrate. Composite silicide and silicon-manganese complex oxide exhibit excellent oxidization resistance, high radiation property and self-healing property. |
| Close |
|
|
|