Anti-ablation behavior of air plasma-sprayed Mo(Si, Al)(2) coating

作者：Hou, Huidong; Ning, Xianjin^*; Wang, Quansheng; Liu, Yanbo; Liu, Ying

来源：Surface and Coatings Technology, 2015, 274: 60-67.

DOI：10.1016/j.surfcoat.2015.04.036

• Mo(Si, Al)(2)
• Induction plasma spheroidization
• Air plasma spraying
• Anti-ablation
• Mixed oxide

The feedstock powder of Mo(Si, Al)(2) (33.3Mo, 40.0Si, 26.7Al, at.%) with dominant C40 phase was prepared by self-propagating high-temperature synthesis and induction plasma spheroidization. Air plasma spraying was applied to deposit Mo(Si, Al)(2) coating on the substrate of niobium alloy. The anti-ablation property of the coating was investigated under supersonic flame at 1400 degrees C for 600 s. The microstructure and ablation mechanism of coatings were studied. The results show that Mo(Si, Al)(2) coating exhibited superior anti-ablation property without spallation and spattering during the whole exposure time. After ablation, an oxide scale of 5-7 pm thick was formed on the well-preserved rigid surface of coating. Below the oxide scale, Mo(Si, Al)(2) was replaced by a continuous Mo5Si3 layer due to the quick dissipation of aluminum. A large area of Mo(Si, Al)(2) immediately beneath oxide scale is depleted in aluminum. The mixed oxide of silica, mullite and alumina is the key point to resist ablation of supersonic flame.

• 出版日期2015-7-25
• 单位北京理工大学