TY - JOUR A1 - Yao, Dongxu A1 - Xia, Y. A1 - Zuo, K.-h. A1 - Jiang, D. A1 - Günster, Jens A1 - Zeng, Y.-P. A1 - Heinrich, J.G. T1 - The effect of fabrication parameters on the mechanical properties of sintered reaction bonded porous Si3N4 ceramics JF - Journal of the European Ceramic Society N2 - Porous silicon nitride ceramics were prepared via sintered reaction bonded silicon nitride at 1680 °C. The grain size of nitrided Si3N4 and diameter of post-sintered ß-Si3N4 are controlled by size of raw Si. Porosity of 42.14–46.54% and flexural strength from 141 MPa to 165 MPa were obtained. During post-sintering with nano Y2O3 as sintering additive, nano Y2O3 can promote the formation of small ß-Si3N4 nuclei, but the large amount of ß-Si3N4 (>20%) after nitridation also works as nuclei site for precipitation, in consequence the growth of fine ß-Si3N4 grains is restrained, the length is shortened, and the improvement on flexural strength is minimized. The effect of nano SiC on the refinement of the ß-Si3N4 grains is notable because of the pinning effect, while the effect of nano C on the refinement of the ß-Si3N4 grains is not remarkable due to the carbothermal reaction and increase in viscosity of the liquid phase. KW - Porous ceramics KW - Silicon nitride KW - Reaction bonding KW - Anisotropic grain growth KW - Ceramic PY - 2014 DO - https://doi.org/10.1016/j.jeurceramsoc.2014.06.018 SN - 0955-2219 SN - 1873-619X VL - 34 IS - 15 SP - 3461 EP - 3467 PB - Elsevier CY - Oxford AN - OPUS4-32542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hu, H.-L. A1 - Zeng, Y.-P. A1 - Xia, Y. A1 - Yao, Dongxu A1 - Zuo, K.-H. A1 - Günster, Jens A1 - Heinrich, J.G. T1 - Rapid fabrication of porous Si3N4/SiC ceramics via nitridation of silicon powder with ZrO2 as catalyst JF - Ceramics international N2 - Porous Si3N4/SiC ceramics were rapidly prepared with Y2O3 as sintering additive and ZrO2 as nitrided catalyst, using Si and SiC as starting powders. Porous Si3N4/SiC ceramics with 5 wt% ZrO2 addition showed a complete nitridation and good mechanical properties (with a high porosity of 34.96%, flexural strength of 150±4.2 MPa, linear shrinkage of 0.02%). It was revealed that the reciprocal formation of ZrO2 and ZrN effectively enhanced nitridation by inhibiting the melting of silicon in micro-regions. KW - D. ZrO2 KW - Rapid nitridation KW - Si3N4/SiC porous ceramics PY - 2014 DO - https://doi.org/10.1016/j.ceramint.2013.11.098 SN - 0272-8842 SN - 1873-3956 VL - 40 IS - 5 SP - 7579 EP - 7582 PB - Ceramurgia CY - Faenza AN - OPUS4-30295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -