【摘要】 研究了A lC l3-S iC l4-H2-CO2气相系统不同温度化学气相沉积(Chem ica l vapor depos ition,CVD)A l2O3-S iO2系氧化物相组成及显微结构,分析了不同温度下气相的渗透效果和550℃沉积产物的相演化。结果表明,1 050℃沉积薄膜由多晶致密-αA l2O3,3A l2O3.2S iO2,少量-δA l2O3,-ιA l2O3和非晶S iO2组成,850℃沉积薄膜由多孔-δA l2O3结合非晶S iO2组成,550℃沉积薄膜由致密-γA l2O3结合非晶S iO2组成。550℃的化学气相渗透(Chem ica lvapor in filtration,CV I)过程有良好的渗透性,可以制备N ex te l 720/A l2O3-S iO2复合材料。进一步研究表明,550℃化学气相沉积出的A l2O3-S iO2复合氧化物经1 350℃热处理可转化为-αA l2O3结合莫来石相。更多还原

【Abstract】 The composition and microstructures of the Al₂O₃-SiO₂compound coatings fabricated by the chemical vapor deposition in the AlCl₃-SiCl₄-H₂-CO₂gas system are investigated.The penetrability of the gas phase at different temperatures and the mullitization behavior of the Al₂O₃-SiO₂coating deposited by CVD at 550℃ are analyzed.The coatings deposited at 550℃,850℃ and 1 050℃ are composed of dense γ-Al₂O₃-SiO₂,pore δ-Al₂O₃-SiO₂,dense α-Al₂O₃-3Al₂O₃·2SiO₂-δ-Al₂O₃-ι-Al₂O₃-SiO₂,respectively.Nextel 720/Al₂O₃-SiO₂ composites can be obtained by CVI at 550℃ because of the good penetrability.The Al₂O₃-SiO₂ matrix can be changed into the mullite matrix by the heat-treatment at 1 350℃.更多还原