复杂结构的压电陶瓷成型工艺研究

Study on casting process of piezoelectric ceramics with complicated structure

快速成型和凝胶注模的有机结合是制备复杂结构陶瓷体的有效方法，该工艺的关键是制备高固相、低黏度的注模浆料,采用快速成型和凝胶注模制备复杂结构的PMN—PZT压电陶瓷，重点讨论了分散剂、浆料pH值和球磨时间对注模浆料黏度的影响，并对该工艺和传统模压成型工艺制备的样品进行了形貌分析和电学性能测定．结果表明：当分散剂用量在0．9％～1．1％，pH值为10．5～11．5，球磨时间为8h时，可以制备出固相含量为55％，黏度小于1Pa·S的压电陶瓷浆料．使用该浆料制备的复杂结构压电陶瓷体与模压成型工艺相比，显微结构均匀致密、晶粒大小与晶界分布均匀，气孔率更小，电学性能更均匀．

Rapid prototyping combining gelcasting is one of effective methods to make complicated structure ceramics, whose key problem is to prepare slurry with high solid loading and low viscosity. The effects of dispersant, pH value, milling time on rheological property of slurry are investigated for PMN -PZT piezoelectric ceramics in this paper. The samples by rapid prototyping-gelcasting and die press are analysed by scanning electron microscopy and electrical properties test. Results show that the piezoelectric ceramics suspension with 55vo1% solid loading and below 1 Pa · s viscosity is prepared when dispersant content is 0. 95wt% - 1.05wt%, pH 10. 5 - 11.5, milling time 8 hours. The samples have a homogeneous microscopic structure, uniform grain size and grain boundary, low porosity and excellent electrical properties in comparison with those of die pressed ones.