Liquid-phase assisted flash sintering of SiC from powder mixtures prepared by aqueous colloidal processing

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• 作者：Victor M. Candelario^a ; Rodrigo Moreno^b ; Richard I. Todd^c ; Angel L. Ortiz^a ; ^{alortiz@unex.es" class="auth_mail" title="E-mail the corresponding author}
• 关键词：SiC ; Flash sintering ; Liquid-phase assisted densification ; Microstructure ; Aqueous colloidal processing
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：37
• 期：2
• 页码：485-498
• 全文大小：5562 K

文摘

The effects were investigated of the starting particle size (i.e., nanometer or submicrometer powders), content of Y₃Al₅O₁₂ additives (YAG; in the range 5–20 wt.%), and difference of size scales between the two particle types on the liquid-phase assisted flash sintering of SiC from powder mixtures prepared by aqueous colloidal processing. It was found that flash sintering benefits from the refinement of the particles size, the increase in additive content, and the smaller size scale of the particulate additive. It was also found that under the present flash sintering conditions (i.e., 900 °C furnace temperature, 13 A current, and 50 s in flash state) the resulting ceramics are, despite the formation of liquid phase, porous to a greater or lesser extent, and exhibit decreasing porosity gradients from their surface to the centre. These observations are rationalized to extract guidelines for powder batch design contributing to the pressureless ultrafast sintering of non-oxide advanced ceramics.