杂质对热压碳化硼陶瓷显微结构和性能的影响
Effect of impurity on microstructure and properties on hot-pressed boron carbide ceramics
周志辉 1张梅 1袁铁锤 1徐运保 2李瑞迪1
作者信息
- 1. State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China
- 2. Hunan Institute of Engineering,Xiangtan 411100,China
- 折叠
摘要
了解杂质元素对碳化硼陶瓷质量的影响,控制杂质元素具有重要意义.在相同的条件下,采用热压烧结方法对不同杂质含量的碳化硼粉末进行了烧结,在烧结过程中发现了一组聚集孔和次生相.分析了烧结过程中杂质的反应和分布.讨论了杂质对致密化和孔隙生成的作用机理.结果表明,Fe2O3和SiO2与碳化硼反应生成FeB、FeB4和Si5C3,杂质形成明显的聚集孔,促进晶粒异常长大,对烧结B4C试样的硬度和强度影响不明显,但使烧结B4C试样的韧性从(1.97±0.03)MPa·m1/2急剧下降到(0.33±0.04)MPa·m1/2.
Abstract
It is very important to understand the influence of impurity elements on the quality of boron carbide and control impurity elements.In the present work,boron carbide powders with different impurity levels were sintered by hot pressing under the same conditions,in which a set of aggregation pores and secondary phases can be detected.The reaction and distribution of impurities in the sintering process were analyzed.The mechanism of impurities on densification and pore generation is discussed.It can be found that the Fe2O3 and SiO2 will react with boron carbide to form FeB,FeB4 and Si5C3,and the impurities cause significant aggregation pores and promote the abnormal grain growth,which have an unapparent influence on hardness and strength but sharply decline the toughness of sintered B4C samples from(1.97±0.03)MPa·m1/2 to(0.33±0.04)MPa·m1/2.
关键词
碳化硼/碳热还原/杂质/晶粒生长/断裂韧性Key words
boron carbide/carbothermal reduction/impurity/grain growth/fracture toughness引用本文复制引用
基金项目
National Natural Science Foundation of China(52272077)
Hunan Provincial Natural Science Foundation,China(2021JJ30856)
出版年
2023
NETL
NSTL
维普
万方数据