Inhibiting crystallization of fused silica ceramic at high temperature with addition of α-Si3N4. Issue 8 (15th April 2021)

• Record Type: Journal Article
• Authors: Liu, Jun; Wang, Qinghu; Li, Yawei; Liang, Xiong; Wang, Xueqing; Sang, Shaobai; Pan, Liping; Xu, Yibiao
• Is Part Of: Ceramics international. Volume 47:Issue 8(2021)
• Page Start: 11394
• Page End: 11404
• Publication Date: 2021-04-15
• Subjects: Fused silica ceramic -- Crystallization -- α-Si3N4; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.12.266
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Fused silica (SiO2 ) ceramic crucibles with α-Si3 N4 coating are commonly used for smelting photovoltaic silicon (Si). However, SiO2 ceramics will inevitably undergo crystallization and large volume change during the high-temperature service, which will lead to crucible cracking and deteriorate the quality and yield of the Si ingot. In this work, α-Si3 N4 /SiO2 ceramics are fabricated by introducing α-Si3 N4 into SiO2 ceramics to inhibit crystallization. The results show that the introduction of α-Si3 N4 can effectively inhibit crystallization of SiO2 ceramics at temperature higher than 1450 °C. Only 5 wt% cristobalite form in SiO2 ceramic with 20 wt% α-Si3 N4 (heated at 1550 °C for 30min). The crystallization activation energy of SiO2 ceramic containing 20 wt% α-Si3 N4 increases by 2.27 times to 931.2kJ/mol compared with that of pure SiO2 ceramic (409.6kJ/mol). The inhibition crystallization effect and increased activation energy derive from the in-situ formation of O–Si–N chemical bond and physical isolation of SiO2 particles by α-Si3 N4 powders.