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| 摘要: |
| 从热力学、动力学和整体控速过程探讨了氮化硅陶瓷材料高温氧化理论和氧化性质,在空气中的热化过程, 因为PO2>Psio, 是纯化氧化过程,氧化产物为SiO2和N2.氧扩散是控制氧化速度的主导因素.氧在Al2O3中的高温扩散系数为10-15~10-14量级,而在SiO2中扩散系数为10-8量级,因此人们探索各种方法在Si3N4陶瓷表面改性以提高其抗氧化性能,其中, 制备金属氧化物的效果显著.在试验沉积Al2O3薄膜的基础上,讨论了Al2O3薄膜对氮化硅陶瓷抗氧化性能的作用,并且展望了精密氮化硅陶瓷表面形成具有良好结合力的金属氧化物-氧化硅混合结构表层的表面改性技术. |
| 关键词: 氮化硅 氧化理论 表面改性 |
| DOI： |
| 分类号:TG174.453 |
| 基金项目:国防预研基金资助项目(项目编号略) |
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| The Ooxidation Theory and Developing State of Researches on Oxidation Resistance of Silicon Nitride at High Temperature |
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Feng Jian-ji1 Li Guo-qing1 Mu Zong-xin1 Zhang Chang-rui2
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| Abstract: |
| This paper reviewed the high temperature oxidation theory of Si3N4 from thermodynamic, kinetics and controlling factors. The oxidation of Si3N4 in air is passive oxidation, Po2>PsiO, The production chemicals are SiO2 and N2, the diffusion coefficient of oxygen in SiO2 is the main controlling factor of oxidation rate. Due to Oxygen diffusion coefficient in Al2O3 is 10-15~10-14 , much more than that in SiO2 as 10-8, so many modification methods were investigated to increase the oxidation resistance, the technology of metal oxide coating is the best way. In this paper, based on the experience of depositing Al2O3 film on surface of Si3N4, the effect of Al2O3 film was discussed and the technique of forming mixed structures of SiO2 and metal oxides for precision ceramics parts of Si3N4 was looked forward.. |
| Key words: silicon nitride,oxidation theory,surface modification |
