(1. 北京科技大學 材料學院，北京 100083；
2. 清華大學 材料科學與工程系 新型陶瓷與精細工藝國家重點實驗室，北京 100084)
摘 要: 由叔丁醇、丙烯酰胺和SiC粉及燒結(jié)助劑組成固相含量為10%(體積分數(shù))的陶瓷漿料，采用凝膠注模成型和無壓燒結(jié)工藝制備多孔SiC陶瓷，研究Al2O3和Al2O3+SiO2這兩種燒結(jié)助劑體系對多孔SiC陶瓷的氣孔率、顯微結(jié)構(gòu)和力學性能的影響。結(jié)果表明：Al2O3+SiO2復合燒結(jié)助劑明顯改善SiC陶瓷的燒結(jié)性能，與采用單一的Al2O3燒結(jié)助劑相比，SiC樣品的燒結(jié)溫度和莫來石的生成溫度均降低50 ℃左右；兩種不同的燒結(jié)助劑制成的試樣中的氣孔均呈很窄的單峰分布，中位孔徑為2 μm左右；隨燒結(jié)溫度的升高壓縮強度增大，而氣孔率變化不大；以Al2O3+SiO2為燒結(jié)助劑、在1 400 ℃燒結(jié)的試樣的氣孔率和強度分別達到70.57%和17. 74 MPa。
關(guān)鍵字: 多孔陶瓷；SiC；燒結(jié)助劑；燒結(jié)性能；凝膠注模；叔丁醇
（1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering,
Tsinghua University, Beijing 100084, China）
Abstract:The porous SiC ceramics were fabricated by gel-casting and pressureless sintering process in air atmosphere with a solid loading of 10% slurry constituting of tert-butyl alcohol, acrylamide, SiC powder and sintering additives. The effects of two kinds of sintering additives, Al2O3 and Al2O3+SiO2, on the porosity, microstructure and mechanical properties of the porous SiC ceramics were studied. The results show that the sintering additive of Al2O3+SiO2 obviously improves the sinterability of SiC ceramics, and compared with that only using Al2O3 as sintering additive, both sintering temperature of SiC specimen and formation temperature of mullite phase are decreased by about 50 ℃. The median pore diameter of the porous SiC ceramics is about 2 μm and presents single peak distribution. The compressive strength of the porous SiC ceramics increases with increasing the sintering temperature, whereas the porosity has little change. Using Al2O3+SiO2 as sintering additive, the porosity and compressive strength of SiC porous ceramics sintered at 1 400 ℃ reach 70.57% and 17.74 MPa, respectively.
Key words: porous ceramics; SiC; sintering additive; sintering properties; gel-casting; tert-butyl alcohol
