Enhancing densification rate and the unusual 4H-SiC polytype stabilization in Ultrafast High-temperature Sintering of α-SiC
Enhancing densification rate and the unusual 4H-SiC polytype stabilization in Ultrafast High-temperature Sintering of α-SiC
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DOI：
10.1016/j.jeurceramsoc.2023.09.038
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发表时间：
2023-09
影响因子：
5.7
通讯作者：
Fei Zuo;Ya-Ning Deng;Zexiao Liu;Qi Li;Salvatore Grasso;Yu-Xiang Xu;B. Jiang;Qiang-Guo Jiang;Hua-Tay Lin;Li-guo Wang
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文献类型：
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作者：
Fei Zuo;Ya-Ning Deng;Zexiao Liu;Qi Li;Salvatore Grasso;Yu-Xiang Xu;B. Jiang;Qiang-Guo Jiang;Hua-Tay Lin;Li-guo Wang
新型粉末介质基超快高温烧结（P-UHS）技术为大尺寸、难烧结、形状复杂的陶瓷材料的超快烧结提供了前所未有的机遇。结果表明，在1500 ° C/min以上的升温速率下，P-UHS是一种非常有效的致密化大尺寸α-SiC块体（≥ 16 cm 3）的方法，在6 min内即可获得致密度≥ 97%、显微结构均匀的块体陶瓷。与传统烧结工艺相比，超快加热使致密化率提高了两个数量级，节能90%。此外，只有当采用超快加热速率时，才观察到优先的4H-SiC多型稳定化。非平衡瞬态化学和超快速收缩被认为是这种不寻常现象的主要驱动力。
Novel Powder medium-based Ultrafast High-temperature Sintering (P-UHS) technique brings unexplored opportunities for the ultrarapid consolidation of large-sized and difficult-to-sinter ceramics with a complex shape. Herein, the P-UHS was demonstrated to be very effective means for the densification of large-sized α-SiC bulks (∼16 cm3) with boron and carbon additions under heating rates exceeding 1500 °C/min. Bulk ceramics with ∼97% density and homogenous microstructure were obtained within only 6 min. The ultrafast heating led to two orders of magnitude increase in the densification rate contributing to an energy saving of 90% if compared to conventional sintering process. In addition, the preferential 4H-SiC polytype stabilization was observed only when ultrafast heating rate was employed. The non-equilibrium transient chemistry and the ultrarapid shrinkage were considered as the major drivers for this unusual phenomenon.