ZrB2-SiC复合材料凝胶注模成型初探

研究了ZrB2-SiC复合材料的凝胶注模成型技术。着重讨论了分散剂、pH值、固相体积含量、有机单体等对ZrB2-SiC复合材料料浆的影响;分析了凝胶注模成型后,排胶前复合材料素坯断面的显微结构以及相对应的烧结体的显微结构。结果表明:当分散剂用量为8.74‰(质量分数),pH为10.8,有机单体含量为3.1%时,可制得固相体积含量为40%,粘度为610mPa.s的ZrB2-SiC复合浆料,此时烧结体的断面主要以穿晶断裂为主;凝胶注模成型的坯体内部的有机聚合物网络因高温而完全分解,使素坯的气孔分布较均匀,利于烧结体致密度的提高。

Study on Gel-Casting Processing of ZrB2-SiC Composites

The gel-casting processing of ZrB2-SiC composites was studied in this research. The effects of dispersant, the pH, the solid volume content and the organic monomer content on slurry were investigated; the microstructure of fracture surface of green bodies and sintering bodies were also studied. The results show that the slurry of solid content 40% and viscosity 610mPa ~ s could be prepared as the content of dispersant is 8.74%v, pH is I0.8 and the organic monomer content is 3.1%. The porosity of sintering bodies is less and trans-granular fracture is the main. The organic binders in the green body removed by baking in vacuum make the pore in green bodies uniformed. It improved that this is well to sintering for the ceramic.