TY - JOUR A1 - Hu, H.-L. A1 - Zeng, Y.-P. A1 - Zuo, K.-H. A1 - Xia, Y. A1 - Yao, Dongxu A1 - Günster, Jens A1 - Heinrich, J. A1 - Li, S. T1 - Synthesis of porous Si3N4/SiC ceramics with rapid nitridation of silicon N2 - Porous Si3N4/SiC ceramics were prepared with Si and SiC as raw materials, Y2O3 as sintering additive and ZrO2 as nitrided catalyst through a rapid nitration process. The nitriding rate as a function of temperature and duration was investigated. The porous Si3N4/SiC ceramics with 8 wt% monoclinic ZrO2 addition that was nitrided at 1400 °C for 2 h exhibited the highest nitridation degree of 95%. The experimental results also demonstrated that the reciprocal formation of ZrO2 and ZrN can effectively enhance the level of nitridation by suppressing the melting of silicon in micro-regions. The effects of nitriding time on the mechanical properties of the specimens with ZrO2 as a catalyst was also studied. After nitrided at 1400 °C for various durations from 2 to 8 h, the porous Si3N4/SiC ceramics with the properties of a porosity over 39.8%, a flexural strength over 88.9 MPa and a linear shrinkage lower than 0.6% were achieved. The systematic investigation reveals the catalytic mechanism of ZrO2 in the synthesis of Si3N4/SiC ceramics. KW - Si3N4 PY - 2015 U6 - https://doi.org/10.1016/j.jeurceramsoc.2015.06.028 SN - 0955-2219 SN - 1873-619X VL - 35 IS - 14 SP - 3781 EP - 3787 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-34956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -