推 荐 人:任 

文献信息1Hai-Long Hu, Yu-Ping Zeng, Kai-Hui Zuo, Yong-Feng Xi, Dong-Xu Yao, Jens Gunster, Jurgen G. Heinrich, Sean Li, Synthesis of porous Si3N4/SiC ceramics with rapid nitridation of silicon, Journal of the European Ceramic Society, 2015, 35, 3781-3787.

推荐理由:氮化硅/碳化硅多孔陶瓷具有气孔率高、热机械性能好和抗热震性优良等特点,被广泛应用于核反应堆、催化剂载体及高温烟气过滤等领域。本文以SiC和单质Si粉为主要原料,采用Y2O3ZrO2为添加剂,通过快速氮化制备了Si3N4/SiC多孔陶瓷,系统研究了ZrO2的添加及氮化时间对材料性能的影响。通过优化工艺参数,在低温快速氮化的基础上制备了气孔率为39.8%、耐压强度为88.9 MPa以及烧后线变化率仅为0.6%Si3N4/SiC多孔陶瓷。作者针对目前非氧化物多孔陶瓷氮化时间长的不足,探明了ZrO2在转变为ZrN的过程对SiC-Si体系的催化氮化作用,对于氮化制备氮化物多孔陶瓷具有很大的借鉴意义。

下载地址:http://dx.doi.org/10.1016/j.jeurceramsoc.2015.06.028

AbstractPorous 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.

文献信息2Daoyang Han, Hui Mei, Shanshan Xiao, Junchao Xia, Jinlei Gu, Laifei Cheng, Porous SiCnw/SiC ceramics with unidirectionally aligned channels produced by freeze-drying and chemical vapor infiltration, Journal of the European Ceramic Society, 37 (2017) 915-921.

推荐理由:SiC多孔陶瓷具有低的体积密度、优异的热震稳定性和化学稳定性,是目前应用于催化和过滤及多孔介质燃烧领域主流的材料之一。目前制备多孔陶瓷众多的方法之中,冷冻干燥法具有制备工艺简便,环境友好等特点;化学气相渗透法是目前最成熟的制备SiC纳米线增强SiC多孔陶瓷的方法。前言部分综述了上述两种方法的最新研究进展,并在此基础上提出将两种方法结合起来,制备具有不定向孔道的SiC纳米线增强SiC多孔陶瓷的新方法。本文为SiC多孔陶瓷气孔结构调控提供了新的思路,对于开拓SiC多孔陶瓷的应用领域具有很好的指导意义。

下载地址:http://dx.doi.org/10.1016/j.jeurceramsoc.2016.10.015

AbstractThe current study introduces a methodology for the fabrication of porous silicon carbide nanowire/silicon carbide (SiCnw/SiC) ceramics with macroscopic unidirectionally aligned channels and reports on thei microstructural and mechanical properties. The material was produced by freezing of a water-based slurry of β-SiC nanowires (SiCnw) with control of the ice growth direction. Pores were subsequently generated by sublimation of the columnar ice during freeze-drying. Chemical vapor infiltration (CVI) of SiC into the open pore network of the SiCnw aerogel with unidirectionally aligned channels, resulted in the formation of highly porous SiCnw/SiC ceramics which exhibited a unique microstructure as identified by scanning electron microscopy. The pore size distribution and the mechanical properties of the asfabricated porous ceramics were examined by mercury intrusion porosimetry and three-point bending and compression tests, respectively, while phase composition was investigated through X-ray diffraction.

本网站由阿里云提供云计算及安全服务 Powered by CloudDream