Abstract

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Author(s):: WEI Taotao; DONG Lin; YANG Guanjun; LIU Meijun; State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China

Keywords:: Silicide coating; ultra-high temperature service; antioxidant mechanism; composite coating; modification

Abstract:: Ultra-high temperature silicide coating has been widely used in high-temperature service components, such as aircraft, spacecraft, rockets, missiles and so on, due to its excellent oxidation resistance at high temperature. However, with the increase of service time and temperature, the oxidation resistance of silicide coating decreases and eventually leads to its failure. In this paper, the research progress of silicide coating systems, preparation methods, failure mechanism and modification methods are reviewed. Silicide coating system can be divided into Si-Cr-X based silicide coating system and refractory metal silicide coating system. Various preparation methods, commonly used for slurry sintering method and powder infiltration method. The failure mechanism is mainly oxidation, thermal expansion coefficient mismatch and thermal diffusion. The coating can be modified by multi-component design, multi-layer gradient structure design and optimization of multiple preparation methods. The new generation of aircraft requires its high-temperature components to be able to serve for a long time at ultra-high temperature (≥1800 ℃), but the current silicide coating cannot meet this condition. Therefore, the future development direction is to develop composite silicide coating for service under ultra-high temperature conditions.