网眼多孔陶瓷浸渍成型工艺的研究

Impregnating Process of Reticulated Porous Ceramics Using Polymeric Sponges as the Templates

采用一种具有三维网状结构和连通气孔的氨酯海绵作为骨架来制备网眼多孔陶瓷．采用一种亲水憎水平衡值（ＨＬＢ）＞１２的表面活性剂溶液对海绵体孔筋表面进行改性处理，改善了海绵与水基浆料之间的粘附性，增加了浆料涂覆量．研究了浆料固含量、有机泡沫体网眼大小、对辊间距和挤压次数对浆量涂覆量及结构均匀性的影响．结果表明：浆料固含量和对辊间距是影响涂覆量及结构均匀性的最主要因素．还发现网眼烧结体的相对密度与相对对辊间距具有很好的线性关系，这为预测和优化材料的渗透率及机械强度提供了一定的依据．

Commercial polyurethane sponges with three dimensional network and open cells, were used as the templates to produce SiC based reticulated porous ceramics (RPCs) from ceramic slurries by the replication process. Surface modification of polyurethane sponges was carried out by a surfactant with hydrophile-lipophile balance (HLB) value>12. This pretreatment is beneficial to increase the adhesion of the slurry to the sponge. Effects of slurry solids content, pore diameter of sponge, distance between the rolls and the number of passes on the loading of slurry on the sponges and macrostructure of RPCs, were investigated in detail. The results indicate that the macrostructure of RPCs depends strongly on the slurry solids content and relative distance. The relative density of RPCs has a good linear relationship with the relative distance, which is very important to predict and optimize the permeability and mechanical properties of RPCs.