先驱体转化制备ZrO_2改性SiC陶瓷的烧蚀行为

Effects of ZrO_2 Addition on Ablation Behavior of Silicon Carbide Ceramics by Precursor Infiltration Pyrolysis Technique

采用先驱体浸渍-裂解法,以聚碳硅烷和正丁醇锆为原料高温裂解制备了ZrO2改性的SiC陶瓷材料,采用氧乙炔焰对材料进行烧蚀实验,结合XRD、SEM和EDS能谱等测试方法,研究了ZrO2的引入对材料烧蚀行为的影响。结果表明:在制备的ZrO2改性SiC陶瓷中,ZrO2以细碎的颗粒状存在于致密的SiC之间。ZrO2的引入提高了SiC陶瓷材料的抗烧蚀性能,引入质量分数为29%ZrO2后,SiC陶瓷的质量烧蚀率由0.0412g/s降低为0.0195g/s,烧蚀后材料未发生断裂。构建了烧蚀行为模型,可知ZrO2在烧蚀后能相对稳定的存在于烧蚀中心,而SiC被氧化为SiO2向四周流失。

ZrO2 modified silicon carbide ceramics were prepared with polycarbosilane and Zirconium n-butoxide as starting materials by the precursor infiltration pyrolysis technique, and behavior of oxyacetylene torch ablation was investigated by XRD, SEM and EDS method. The result shows that ZrO2 exists as a grain form among the SiC block in the as-received ceramics. Ablation resistance of SiC ceramics is improved after ZrO 2 addition. The mass loss of 29 wt% ZrO2 doped SiC ceramics is 0.0195 g/s which is evidently lower than that of SiC ceramics (0.0412 g/s), and after ZrO2 is introduced the material stays more integrated. The ablation model is set up, and it proves that ZrO2 exists as a steady phase in the ceramics which enhances the ablation resistance of the ceramics while SiC is easy to be blowed to the edge region.