造孔剂对多孔碳化硅陶瓷制备工艺和抗弯强度的影响

Effect of Pore Former on Fabrication Process and Bending Srength of Porous Silicon Carbide Ceramics

研究了造孔剂石墨和淀粉对多孔碳化硅陶瓷制备工艺和抗弯强度的影响。结果表明:石墨中含有碳和SiO2等成分,碳在高温烧结过程中因氧化而排出,较好地保留了气孔,SiO2补充了烧结助剂,降低了烧结温度;而淀粉在烧结过程中氧化完全,烧结温度偏高;将质量分数分别为70%的碳化硅、20%的石墨和10%的烧结助剂混合成型后,在空气中于1 270℃烧结2h可制备出开孔率为43.8%、抗弯强度为19.6MPa的多孔碳化硅陶瓷。

Effects of graphite and starch pore former on fabrication process and bending strength of porous silicon carbide （SIC） ceramics were studied. The results show that because graphite contained carbon, silica and so on, carbon was oxidized and exhausted during sintering at high temperature, and continuous pores were left among sic particles; moreover, the silica added the sintering aids so that sintering temperature decreased. However, starch was oxidized all during sintering and sintering temperature was higher. Porous SiC ceramics with porosity of 43. 8% and bending strength of 19.6 MPa was prepared with 70wt%SiC, 20wt% graphite and 10wt% sintering aids at 1 270℃ for 2 h in atmosphere.