摘要
碳化硼陶瓷具有极高的硬度和良好的热传导性能,但这些性能极大地依赖于其化合硼碳比。当化合硼碳比偏离4(B_(4)C)时,其性能会有大幅下降。本研究以几种商业碳化硼粉体为研究对象,通过对其X射线衍射谱图的细致分析,从重叠峰中分离出富硼碳化硼的衍射峰并进行标定。在此基础上,研究了不同烧结工艺下碳化硼陶瓷的物相组成及富硼相的转变过程。研究结果表明,商业碳化硼粉体通常为B_(4)C与B_(4)C等富硼相及其他杂相的混合相。XRD及拉曼光谱结果显示,在热压烧结过程中,粉体中的富硼相会与游离碳反应生成B_(4)C,采用商业碳化硼粉在2100℃、40 MPa条件下热压60 min制备得到了纯相的B_(4)C陶瓷。
Boron carbide ceramic has been known to possess ultrahigh hardness and goo d thermal conductivity.However,these properties greatly depend on the phase composition of boron carbide,that is,the B/C ratio.As the combined B/C ratio in boron carbide deviates from the stoichiometry of B_(4)C,all these properties decrease dramatically.In this study,the phase compositions of several commercial boron cabide powders were confirmed through the detailed analysis of their X-ray diffraction patterns,from which the diffraction peaks of the boron-rich phases were separated and calibrated from the overlapping peaks.The final phase compositions of hot pressed boron carbide ceramics and the transformation process of boron-rich phases to B_(4)C at different sintering temperatures were then investigated.The results show that the commercial boron carbide powder is usually a mixture of B_(4)C and boron-rich phases such as B_(4)C as well as other impurities.The results of X-ray diffraction and Raman spectroscopy show that the boron-rich phases react with free carbon to form B_(4)C as the sintering temperature increases.A boron carbide ceramic with pure B_(4)C phase is prepared using commercial boron carbide powder by hot pressing at 2100℃and 40 MPa for 60 min.
作者
魏一统
瞿志学
吉雅柔
冯航航
Wei Yitong;Qu Zhixue;Ji Yarou;Feng Hanghang(Key Laboratory of Advanced Functional Materials,Education Ministry of China,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2022年第4期1385-1390,共6页
Rare Metal Materials and Engineering
基金
北京市自然科学基金(2182007)
北京市属高校高水平教师队伍建设支持计划青年拔尖人才培育计划(CIT&TCD201704031)。
关键词
碳化硼
热压烧结
富硼碳化硼
硼碳比
boron carbide
hot pressing sintering
boron-rich phases
B/C ratio
