干法纺丝制备二硼化锆陶瓷纤维及其表征

Preparing Zirconium Boride(ZrB_2) Ceramic Fiber by Dry Spinning and Its Characterization

二硼化锆是一种很具潜力的超高温陶瓷材料。通过干法纺丝手段可以得到具有一定优良性能的二硼化锆纤维:以二硼化锆陶瓷制备中的液相前驱体转化技术为依据,采用八水合氧氯化锆、硼酸、蔗糖和柠檬酸为原料,并利用聚乙烯醇为纺丝助剂,制得二硼化锆前驱体纺丝液,然后利用干法纺丝制得前驱体纤维,通过高温烧结制得二硼化锆陶瓷纤维。仪器分析结果如下:通过同步热分析仪(TG-DSC)分析前驱体纤维在100℃~1400℃的失重情况,发现二硼化锆纤维在1200℃左右生成;采用X射线衍射(XRD)和X射线光电子能谱分析(XPS),发现陶瓷纤维中二硼化锆晶形完整且含量较高;通过陶瓷纤维的X射线能谱分析(EDS)及元素分析(EA),发现纤维产物的纯度也较高;另外,扫描电镜(SEM)、单丝强度测试和热失重(TG)分析结果表明:干法纺丝制得的陶瓷纤维表面光滑,强度较好,具有一定的耐高温性。

ZrB2ceramic is potentially one of the ultra-high temperature ceramics.ZrB2ceramic fiber with excellent properties was successfully synthesized via dry spinning method.Precursor solution for ZrB2by dryspinning was prepared by distilling the mixture of the solution that was made from ZrOCl2·8H2O,boric acid, sucrose,and citric with polyvinyl alcohol solution as spinning assistant.ZrB2ceramic fiber was obtained by pyrolyzing the dry-spinning fibers at elevated temperature.Using TG-DSC device,thermal degradation of ZrB2 ceramic fiber from temperature 100℃ to 1400℃ can be analyzed,showing that fibers start to grow at near 1200℃.ZrB2ceramic fiber has regular crystal shape and high purity according to the results of XRD and XPS analysis.Besides,results from SEM,strength tests and TG analysis indicate that ZrB2ceramic fiber from dryspinning process has smooth surface,high strength and can tolerate relatively high temperature.