定向冷冻铸造工艺制备的层状SiC多孔陶瓷微观结构分析

Microstructure Analysis of SiC Porous Peramics with Lamellar Structure Prepared by Directional Freeze-casting Process

采用定向冷冻铸造工艺制备层状SiC多孔陶瓷材料,分析了孔隙微观结构,探讨了孔隙的形成机制。研究结果表明:距冷源平面的距离决定孔的隙形貌和分布;试样纵截面可分为致密区、过渡区和层片区;在冰晶生长方向,孔隙形貌由柱状向层状转变,过渡区孔隙呈板条状,孔径(层片厚度)增大。

The SiC porous ceramics material with directional lamellar structure was prepared by directional freeze-casting process. The microstructure of pores was analyzed, and the forming mechanism of pores was discussed. The results show that the distance from cold source plane decides morphology and distribution of pores. The longitudinal cross section of samples can be divided into three regions: compact region, transition region, lamellar region. Along the growth direction of ice crystal, the pore morphology changes from columnar to lamellar and the pores of transition region is lath, and the pore size(lamella thickness) increases.