溶胶-凝胶法Al_2O_3涂覆钨纤维的制备及组织特性  

Preparation of Al_2O_3 Coating on Tungsten Fibers by a Sol-Gel Method and Its Microstructure Characteristics

作　　者：马运柱[1] 叶晓珊[1] 刘文胜[1] 黄倩芳[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《稀有金属材料与工程》2014年第10期2483-2488,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50774098)

摘　　要：采用溶胶-凝胶法在钨纤维的表面制备Al2O3涂层,用热分析(TG-DSC)、X射线衍射(XRD)、扫描电镜(SEM)和电子能谱仪(EDS)等方法研究钨纤维表面Al2O3涂层在不同干燥工艺、不同PVA添加量和不同煅烧温度下的组织特征。结果表明:采用分步干燥工艺可以避免涂层团聚和开裂;溶胶制备中加入体积分数为5%的聚乙烯醇(PVA)可以提高溶胶稳定性,有利于制备均匀且无裂纹的Al2O3涂层;钨纤维表面Al2O3涂层制备的最佳煅烧温度为950℃;采用Al2O3涂覆的钨纤维抗氧化温度提高了120℃,氧化增重减少了约9%。Aluminum oxide coating on the surface of tungsten fibers was prepared by a sol-gel method.The microstructure characteristics of Al2O3 coating with different contents of PVA additive,different drying processes and different calcination temperatures were studied by TG-DSC,XRD,SEM and EDS.The results show that coating agglomerations and cracks can be avoided via the step-by-step drying process.5 vol% PVA addition enhances the stability of the sol greatly and the uniform and crack-free Al2O3 coating on the surface of tungsten fibers can be achieved.The best calcining temperature is 950 oC for the coating.Antioxidation temperature is increased by 120 oC and the oxidation mass is reduced by about 9% for Al2O3-coated tungsten fibers compared with tungsten fibers.

关 键 词：钨纤维 溶胶-凝胶法 AL2O3涂层 显微组织 

分 类 号：TQ343[化学工程—化纤工业]