SiC-TiB_2复合陶瓷凝胶注模成形研究

Study on Gel Casting Processing of SiC-TiB_2 Composite Ceramics

研究了Si C-Ti B2复合陶瓷的凝胶注模成形技术。重点讨论了p H值、分散剂对Si C-Ti B2水基复合浆料粘度的影响,以及不同的单体含量对复合陶瓷坯体密度的影响,分析了坯体热失种曲线以及断口的微观形貌。结果表明:选用的三种分散剂的分散效果大小顺序为:聚乙烯亚胺(PEI)>四甲基氢氧化铵(TMAH)>聚甲基丙烯酸铵(PMAA),且三种分散剂的最佳加入量分别为:0.1%、0.4%、0.1%,最佳p H值为10,凝胶注模成形坯体致密,颗粒分布均匀,随着单体含量的增加,坯体的密度会有所增加,但是单体含量较高时,坯体干燥过程中变形量大,而且烧结成品易出现开裂的情况。

The gel-casting processing of SiC-TiB_2 composite ceramics was studied in this research. The effective factors of the viscosity of SiC-TiB_2 aqueous slurry,such as p H value,dispersants were investigated. The influence of monomer contents on the density of green body was studied. TG-DTA was used to measure the weight loss and SEM was used to observe the fracture appearance of green body. Results show that the effect of dispersants on slurry viscosity is in order of： PEI TMAH PMAA,and optimum content are： 0. 1%,0. 4% and 0. 1%,respectively.The slurry reach best dispersion at pH = 10. After gel casting,the ceramic green body have uniform particle size distribution. The density of green body achieve 1. 9 g / cm^3,better than those by dry-pressure. Density increased with the increase of monomer with different content. However,high monomer content can be easily to cause high deformation of green body and crack after sintering.