Analysis on the oxidation behavior of Mo5Si3MoSi2/SiC multi-coating at high temperature

作者：Yang Xin; Zou Yanhong; Huang Qizhong^*; Su Zhe'; an; Chang Xin; Xie Zhiyong; Zhang Mingyu

来源：Acta Materiae Compositae Sinica, 2009, 26(4): 119-125.

• Anti-oxidation
• Anti-oxidation coating
• Anti-oxidation properties
• Chemical vapor reaction
• Coated sample
• High temperature
• Initial oxidation
• Isothermal oxidations
• Mass gain
• Mass loss
• Mo5Si3
• MoSi2
• Oxidation behaviors
• Passive oxidation
• Room temperature
• SEM and EDS analysis
• SiC
• Slurry method
• Thermal shock resistance
• XRD

To improve the anti-oxidation property of graphite at high temperature, an Mo5Si3-MoSi2/SiC multi-coating was prepared by the chemical vapor reaction (CVR) and slurry method. The structure of the multi-coating was studied by XRD, SEM and EDS analysis, and the oxidation behavior of the multi-coating at high temperature was investigated by the isothermal oxidation test and thermodynamics calculation. The results show that the Mo5Si3 and MoSi2 phases in the multi-coating are prone to produce the reactions of forming the MoO3 gas in air at 1823 K and result in the mass loss, while the mass gain in the initial oxidation stage (0-6 h) is primarily attributed to the dominating passive oxidation of SiC. As the main phases of the multi-coating can oxidize and form the SiO2 glass at high temperature, it enables the coating to have the excellent anti-oxidation ability and thermal shock resistance. After oxidation in air at 1823 K for 20 h and thermal cycling between 1823 K and room temperature 16 times, the mass loss of the coated sample is only 3.78%.

• 出版日期2009
• 单位中南大学