孔结构可控的网眼多孔陶瓷的制备

采用一种具有三维网状结构和贯通气孔的有机泡沫体作为载体，首先利用有机泡沫浸渍工艺制备出高气孔率且几乎没有堵孔的网眼素坯，经过排塑、预烧处理获得具有一定强度的预制体．由于未经烧结，预制体的孔筋呈疏松多孔结构．利用粘度较低、流动性很好的浆料对预制体进行涂覆处理．结果表明：通过这种处理，孔筋上的裂纹被消除，非常细的孔筋被避免，孔筋厚度比较均匀，从而获得了结构非常均匀的网眼陶瓷．相对密度、孔筋厚度、孔径大小可以根据徐覆次数来调节．随着涂覆次数的增加，孔径减小，孔筋厚度增加，相对密度也增加．本工作为网眼陶瓷孔结构的精确设计提供了一种新工艺，对于优化其力学性能、渗透率等性能具有重要意义．

Preparation of Reticulated Porous Ceramics with a Controlled Pore Structure

A polymeric sponge with interconnected pores in all three dimensions was chosen to prepare firstly the reticulated preform by the replication process. After the polymeric sponge was burned out, the reticulated preform was presintered to obtain enough operating strength. The struts of the reticulated preform exhibit porous microstructure, which is beneficial to coating of the slurry on them. The coating treatment was conducted by the thinner slurry on the reticulated preform. The typical flaws such as longitudinal strut cracks were eliminated by recoating process; additionally, very thin struts were avoided by coating. The reticulated ceramics with a very uniform macrostructure was produced by recoating process and few filled cells were invisible. The effects of coating numbers on the pore size, strut thickness and relative density were investigated in detail. This work has developed successfully an innovative approach to precisely control the macrostructure for the reticulated ceramics, which is valuable to predict and optimize their properties such as mechanical properties and permeability.