高固含量Si_3N_4/B_4C水基悬浮体的制备

Preparation of Si_3N_4/B_4C aqueous slurry with high suspended solid

高固相、低粘度Si3N4/B4C水基悬浮体的制备是实现陶瓷材料凝胶注模成型工艺的关键和前提。以Si3N4和B4C为初始原料,选择合适的分散剂聚乙烯吡咯烷酮(PVP),通过优选工艺参数,10%的B4C和90%的Si3N4与H2O混合,加入1.5mg/m2PVP,调节pH=10.5,即可制备出固相体积分数为60%,粘度小于1Pa·s的Si3N4/B4C水基悬浮体。

Preparation of Si_3N_4/B_4C aqueous slurry with high suspended solid and low viscosity is an essential step for forming Si_3N_4/B_4C green body by gel casting.However Si_3N_4 and B_4C powders are very difficult to be dispersed.The optimum process conditions for preparing Si_3N_4/B_4 C aqueous slurry with high suspended solid (60% volume ratio) were determined.They are B_4C(10%) and Si_3N_4(90%) were mixed with H_2O,15 mg/m^2 polyvinyl pyrrolidone(PVP) was added into the mixture,and pH=10.5.Rheological properties of the Si_3N_4/B_4 equeous slurries also were studied.The prepared Si_3N_4/B_4C equeous slurry (60% volume ratio) has viscosity is less than 1 Pa·s.