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通过热力学分析研究了超硬无机材料，如ＳｉＣ、Ｓｉ３Ｎ４、ＴｉＣ、ＴｉＮ等纳米粉末的化学气相沉积（ＣＶＤ）合成反应过程和核化过程的有关热力学规律。结果表明：合成物以共价键和以金属键为主的合成反应和化学反应过程对温度、压力均比较敏感，热力学驱动力随温度变化增加比较明显，对外压的敏感表现为增大压力对合成反应不利。合成物以离子键为主时，反应的热力学驱动力随温度变化不明显，外压的影响也不显著。对于核化过程，合成物以金属键和离子键为主的体系，核化所需临界过饱和度较低，ｌｇ（ｐ／ｐ０）在１～１０之间，而对合成物以共价键为主的体系，核化所需过饱和度较高，ｌｇ（ｐ／ｐ０）约在１５～２０之间，因实验过程很难达到这样高的过饱和度，因此合成粉体常以非晶态形式存在，以降低核化阻力
The thermodynamic laws of chemical vapor deposition (CVD) synthesis reaction and nucleation of ultra-hard inorganic materials such as SiC, Si3N4, TiC and TiN have been investigated by thermodynamic analysis. The results show that the synthesis reaction and chemical reaction process are mainly sensitive to temperature and pressure. The driving force of thermodynamics increases with the increase of temperature, and the external pressure is sensitive to the increase of pressure The synthesis reaction is unfavorable. When ionic bond was the main component, the thermodynamic driving force of the reaction did not change obviously with temperature, and the influence of external pressure was not significant. For the nucleation process, the metal-ionic and ionic-bond-based systems of the composites have a lower critical supersaturation, lg (p / p0) between 1 and 10, and the covalent bonds Based system, higher supersaturation required for nucleation, lg (p / p0) is about 15 to 20, due to the experimental process is difficult to achieve such a high degree of supersaturation, so synthetic powder often amorphous State form exists to reduce the nucleation resistance