以球形SiO2颗粒为基体、 硅树脂为粘结剂,通过干压法制备多孔SiO2陶瓷型芯,研究了硅树脂添加量和烧结温度对陶瓷型芯性能的影响.研究结果表明:硅树脂作为粘结剂通过交联、 裂解从而实现对球形SiO2颗粒的包覆和粘结,明显改善了球形SiO2颗粒的烧结性能.在1350℃烧结温度下,随着硅树脂含量增大,型芯样品的失重率不断增大,收缩率反而不断减小;在硅树脂含量为20％时,收缩率仅为0.42％,能较好地保证型芯的尺寸精度;硅树脂含量为10％时,在1300℃烧结2 h,陶瓷型芯室温抗弯强度为11.8 MPa、线性收缩率为0.49％、显气孔率为30.9％,综合性能最佳.%The porous SiO2-based ceramics core were prepared using dry pressing method, where spherical silica powders were used as original materials and silicon resin was used as the binder. The effect of silicone resin content and sintering temperature on the properties of the core samples were examined. The results show that silicone resin as the binder can greatly improve the formation rate of micron-sized spherical powders. Silicone resin coated the spherical SiO2 particles through the cross-linking, cracking, which significantly improved sintering properties of spherical SiO2 particles. Sintered at 1350 ℃, the weight loss rate of samples increased continuously with the increase of silicone resin content. In fact, the weight loss of the sample was mainly caused by decomposition of silicon resin. Shrinkage rate constantly decreased with the increase of silicone resin content. When the silicone resin content was 20％, the shrinkage rate reached an ideal value of 0.42％. The bending strength was 11.8 MPa, the linear shrinkage was 0.49％ and the apparent porosity was 30.9％ after the sample with 10％ silicone resin content was sintered at 1300 ℃for 2 h .
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