高致密碳化硅陶瓷的低温液相烧结  

Low Temperature Liquid Phase Sintering of Highly Dense SiC Ceramics

作　　者：许洁 周小兵 徐凯 常可可 代建清[1] 黄庆 XU Jie;ZHOU Xiaobing;XU Kai;CHANG Keke;DAI Jianqing;HUANG Qing(Kunming University of Science and Technology,Kunming 650000,Yunnan,China;Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315000,Zhejiang,China)

机构地区：[1]昆明理工大学,云南昆明650000 [2]中国科学院宁波材料技术与工程研究所,浙江宁波315000

出　　处：《陶瓷学报》2022年第3期448-454,共7页Journal of Ceramics

基　　金：国家自然科学基金(11975296);宁波市自然科学基金(2021J199)。

摘　　要：SiC陶瓷具有强共价键结构,表面扩散系数较低,其低温烧结致密化一直是业内学者研究的焦点之一。利用Pr_(3)Si_(2)C_(2)与SiC在~1150℃发生低温共晶液相转变可促进SiC烧结的原理,采用熔盐法,在SiC颗粒表面原位生长出Pr_(3)Si_(2)C_(2),促进了Pr_(3)Si_(2)C_(2)烧结助剂与SiC颗粒的均匀分散。通过电场辅助烧结,在1500℃低温下实现了SiC陶瓷的高致密化(气孔率~0.3%),热导率达到106 W·m^(-1)·K^(-1)。通过对SiC陶瓷微观结构分析,其烧结过程为典型的液相烧结溶解—沉淀机制。本文Pr_(3)Si_(2)C_(2)低温烧结助剂的开发为SiC陶瓷及其复合材料的低温烧结提供了实验依据。Low temperature sintering of highly dense SiC ceramics is one of the research focuses of scholars in industries,because of the high degree of Si-C covalent bonding and the low self-diffusion coefficient of SiC.Noting that low-temperature eutectic liquid phase transition between Pr_(3)Si_(2)C_(2)and SiC can promote the sintering of SiC,Pr_(3)Si_(2)C_(2)was grown in-situ on the surface of SiC particles by using a molten salt method,in order to ensure the uniform dispersion of Pr_(3)Si_(2)C_(2)in the SiC particles.SiC ceramics with high density(porosity of 0.3%)and thermal conductivity of up to 106W·m^(-1)·K^(-1) were successfully fabricated,by using electric current field-assisted sintering technology at a low temperature of 1500℃.According to microstructure of the SiC ceramics,it is concluded that the sintering process followed a typical solution-precipitated liquid phase sintering mechanism.Therefore,Pr_(3)Si_(2)C_(2)is a promising low-temperature sintering additive for the low-temperature sintering of SiC ceramics and their composites.

关 键 词：碳化硅 液相烧结 电场辅助烧结 镨硅碳 熔盐法 

分 类 号：TQ174.75[化学工程—陶瓷工业]