Processing and mechanical properties of Si3N4 composites employing polymer-derived SiAlOC as sintering aid
Processing and mechanical properties of Si3N4 composites employing polymer-derived SiAlOC as sintering aid
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DOI：
10.1016/j.jeurceramsoc.2009.08.014
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发表时间：
2010-02
影响因子：
5.7
通讯作者：
T. Plachký;Z. Lenčéš;Ľ. Hric;P. Šajgalík;P. Baláž;R. Riedel;H. Kleebe
中科院分区：
文献类型：
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作者：
T. Plachký;Z. Lenčéš;Ľ. Hric;P. Šajgalík;P. Baláž;R. Riedel;H. Kleebe
用聚合物衍生的SiAlOC助烧结剂对氮化硅陶瓷进行了致密化。在相对温和的温度下（1600°C）从30wt的混合物中制备致密样品。%的热解SiAlOC添加剂。将SiAlOC助剂含量降低至15wt。%产生多孔si3n4样品（雷尔密度约85%）。残余的SiAlOC玻璃（HV=15.5GPa， KIC=4MPam1/2）影响了致密样品的性能。将烧结温度提高到1780℃，烧结5min后，复合材料的相组成和性能发生了显著变化。烧结样品中主要相为O ' -sialon。样品在1530℃下进一步退火16h，进一步减少了残余玻璃相的数量，从而影响了力学性能。致密试样的维氏硬度为18.5GPa，抗断裂强度在4.0 ~ 4.5 mpam /2之间。在1600°C /100MPa/24h下对SNA30-A试样进行了压缩蠕变试验（1400°C/100MPa/24h），结果表明该试样的蠕变速率较低，为8.6×10−8s−1。结晶后样品的抗蠕变性能有望进一步提高。
Silicon nitride ceramics have been densified with polymer-derived SiAlOC sintering aid. Dense samples were prepared at relatively mild temperatures (1600°C) from blends with 30wt.% of pyrolysed SiAlOC additives. Decreasing the SiAlOC aid content to 15wt.% resulted in porous Si3N4samples (∼85% rel. density). The properties of dense samples were influenced by the remaining SiAlOC glass (HV=15.5GPa, KIC=4MPam1/2). Increasing the sintering temperature to 1780°C for 5min significantly changed the phase composition and properties of the composites. The major phase was O′-sialon in the sintered samples. Additional annealing of the samples at 1530°C for 16h further decreased the amount of the residual glassy phase and consequently affected the mechanical properties. The Vickers hardness of dense samples was 18.5GPa and the fracture resistance ranged between 4.0 and 4.5MPam1/2. The compressive creep test (1400°C/100MPa/24h) of the SNA30-A sample sintered at 1600°C for 30min without an additional crystallisation step showed a promising low creep rate of 8.6×10−8s−1. Further improvement of creep resistance is expected for the crystallised samples.