溶胶-凝胶法制备复合材料用氧化铝基体及涂层研究

Preparation of Alumina Matrix and Coating by Sol gel Method

采用溶胶—凝胶法，分别研究了用三种起始物异丙醇铝［Ａｌ（ＯＣ３Ｈ７ｉ）３］、氯化铝（ＡｌＣｌ３·６Ｈ２Ｏ）、硝酸铝［Ａｌ（ＮＯ３）３·９Ｈ２Ｏ）］，制备碳纤维三维编织物增强复合材料用氧化铝基体及涂层的工艺，考察了三种体系反应物配比、水解温度、反应时间等因素对制得的三种溶胶体系性能的影响，获得了较佳的溶胶配制参数；还考察了三种溶胶体系在通常情况下和在编织物中的凝胶化情况，获得了较佳的凝胶化条件；同时还研究了不同条件下三种凝胶的裂解产物及其晶体类型。结果表明，不管经过何种途径，凝胶在经１２６０℃裂解后均可获得α－Ａｌ２Ｏ３。

?Alumina(α-Al 2O 3) used as composite matrix reinforced by three dimensional carbon fiber preform and as coating, was prepared by sol gel method from three starting materials, aluminum iso propanolate [Al(OC 3H 7 i) 3], aluminum chloride (AlCl 3·6H 2O) and aluminum nitrate [Al(NO 3) 3·9H 2O]. Three sols were prepared from hydrolysis of these three starting materials, respectively. The influences of mole ratios of water to reagent, hydrolysis temperature, and hydrolysis time, on the properties of sols were investigated, thus the optimum conditions for sol preparation were obtained. The influences of temperatures on the gelation of the three sols were also analyzed, and the optimum conditions for gelation were obtained. Finally, the influences of pyrolysis temperatures and atmospheres on the final ceramic products and their crystal type of three gels were also studied. The results showed that three gels would convert to α-Al 2O 3 after 1 260℃ any way.