陶瓷涂层SiO_2-Al_2O_3溶胶封孔剂的制备及封孔性能  

Preparation of SiO_2-Al_2O_3 Sol Sealing Reagent for Ceramic Coatings and Its Sealing Performance

作　　者：孟令娟[1] 肖巍[1] 闵捷[1] 张琦[1] 叶菲[2] 叶卫平[2] 程旭东[1] 

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,湖北武汉430070 [2]武汉理工大学材料科学与工程学院,湖北武汉430070

出　　处：《材料保护》2010年第11期20-22,共3页Materials Protection

摘　　要：等离子喷涂技术由于其自身固有的性质,涂层不可避免地存在孔隙,从而使涂层的耐腐蚀性能下降,为了提高涂层的耐腐蚀性能,必须对涂层进行封孔处理。为此,以正硅酸乙酯和硝酸铝为前驱体,无水乙醇和去离子水为溶剂,盐酸为催化剂,采用溶胶-凝胶法在涂层表面制备了一层均匀致密的SiO2-Al2O3封孔层。应用XRD,IR,DTA-TG和SEM等对封孔层的结构、热稳定性和形貌进行了表征。结果表明,封孔层为稳定的非晶态SiO2-Al2O3组织,且均匀致密,表面无明显裂纹;陶瓷层封孔后的耐酸、碱、盐性能均能提高50%以上,从而增强了涂层对基体的保护性能。Plasma sprayed coatings inevitably contain pores, which is harmful to retaining the corrosion resistance of the coatings. This means that sealing treatment is indispensable for improving the corrosion resistance of plasma sprayed coatings. Therefore, SiO2-Al2O3 sol sealing reagent was prepared from ethyl silicate and Al(NO3)3 as the starting materials, in the presence of ethyl alcohol and deionized water as solvents and hydrochloric acid as a catalyst. Resultant sealing agent was then used to prepare a uniform and compact sealing layer on the surface of plasma sprayed ceramic coatings. The structure, thermal stability and morphology of the sealing layer were analyzed by means of X-ray diffraction, infrared spectrometry, differential thermal analysis-thermogravimetric analysis and scanning electron microscopy. It was found that the sealing layer was composed of stable amorphous phase SiO2-Al2O3. The sealing layer was uniform and compact, and contained no cracks. After sealing treatment, the plasma sprayed ceramic coatings possessed improved resistance to acid, base and salt, showing better protective efficiency for the substrate.

关 键 词：封孔剂 SiO2-Al2O3溶胶 等离子喷涂 陶瓷涂层 耐蚀性 热稳定性 

分 类 号：TG174.453[金属学及工艺—金属表面处理]