利用凝胶注模成型工艺将采用选择性激光烧结技术制备的多孔石墨预制体与含莫来石的陶瓷浆料进行复合,经冻干和烧结后得到了石墨/莫来石复合材料;测试分析了各试样的性能,确定了莫来石陶瓷相的合理烧结工艺。结果表明,多孔石墨预制体的开气孔率为60%,密度为0.518 g·cm ^-3,导热系数约为1.01 W·m ^-1·K ^-1,抗弯强度为1.7 MPa。烧结后莫来石的最大相对密度为80.4%,抗压强度为28.3 MPa,抗弯强度为27.5 MPa,导热系数为2.35 W·m ^-1·K ^-1。多孔石墨预制体的后处理可避免复合区域出现裂纹及两相结合不佳的现象,大幅增强了复合材料的整体性与界面结合性。

By the gelcasting process, the porous graphite preform prepared by selective laser sintering is mixed with mullite ceramic slurry, and after freeze drying and sintering, the graphite/mullite composite is obtained. The performance of each sample is tested and analyzed, and the suitable sintering process is determined. The results show that the open porosity, density, thermal conductivity, and bending strength of the porous graphite preform are 60%, 0.518 g/cm 3, 1.01 W·m -1·K -1 and 1.7 MPa, respectively. For the sintered mullite ceramics, the relative density is 80.4%, the compressive strength is 28.3 MPa, the bending strength is 27.5 MPa, and the thermal conductivity is 2.35 W·m -1·K -1. The post-processing of porous graphite preforms can avoid the occurrence of cracks in the combination zone and the poor combination of two phases, and the integrity and interfacial bonding of composites are greatly enhanced.