氮化硅结合碳化硅复合材料性能优化的研究进展

氮化硅结合碳化硅具有优异的力学性能、抗蠕变性能、抗热冲击性能、热学性能和抗化学侵蚀性能,被广泛应用于冶金、化工、机械和国防军工等领域。氮化硅结合碳化硅的服役环境恶劣,材料的力学性能、抗热震性能、抗侵蚀性能和抗氧化性能是影响其服役寿命的关键。本文针对如何提升氮化硅结合碳化硅材料的服役性能,对氮化硅结合碳化硅力学性能、抗热震性能、抗侵蚀性能和抗氧化性能的优化工艺和技术原理进行了总结与归纳。目前,氮化硅结合碳化硅性能优化的主要措施有:(1)合理选择原料的组分配比、颗粒级配、结合系统和烧结制度;(2)添加含Fe、Co、Ni或Cr等催化剂,促进硅粉的氮化和氮化硅晶须的生长;(3)添加烧结助剂或增强相,促进材料的烧结致密化或材料中高熔点第二相的生成。

Research Progress on Performance Optimization of Silicon Nitride Bonded Silicon Carbide Composites

Silicon nitride bonded silicon carbide was widely used in metallurgy,chemical machinery,national defense and military industries due to its excellent mechanical properties,creep resistance,thermal shock resistance,thermal properties and chemical corrosion resistance.The mechanical properties,thermal shock resistance,chemical corrosion resistance and oxidation resistance of silicon nitride bonded silicon carbide are the keys to its service life due to the harsh operational environment.With the purpose of improving the service properties of silicon nitride bonded silicon carbide,the essay has investigated and summarized the performance optimization and technical principle of it from the aspects of mechanical properties,thermal shock resistance,chemical corrosion resistance and oxidation resistance.The main measures to improve the properties of silicon nitride bonded silicon carbide composites include:(1)Selecting the particle gradation,grain composition,combined system and sintering system rationally.(2)Adding catalysts such as Fe,Co,Ni or Cr to promote the nitriding of silicon powders and the growth of silicon nitride whiskers.(3)Promoting the densification of composites materials or the forming of high-melting-point second phase by adding sintering aids or reinforcements.