摘要
采用碳热还原法合成了不同ZrB2含量的LaB6ZrB2复合粉末。通过热压烧结法制备了相应的复合材料,其性能测试结果表明:随着ZrB2含量的增加,LaB6ZrB2复合材料的硬度和弯曲强度均随之增大,而断裂韧性则先增后减,在ZrB2质量分数为21%时,其断裂韧性达最大值。利用金相显微镜和扫描电镜观察多晶试样的微观组织及断口形貌,初步分析了复合材料的增韧机制。
LaB6-ZrB2 composite powders with different contents of ZrB2 were synthesized by the carbon thermo-reduction method and the corresponding polycrystalline composites were fabricated by the hot pressing sintering method. The effects of the ZrB2 content on the microstructure and mechanical properties of the composites were studied. The results show that the hardness and the bending strength of LaB6-ZrB2 poly-crystals are enhanced with the increase of ZrB2 content, while the fracture toughness is increased firstly and decreased afterwards and it reaches the optimum value when the mass fraction of ZrB2 is 21%. The microstructure and the fracture morphology of the composites were revealed by means of metallographic and SEM. The improvement mechanism of the fracture toughness of the composites by adding ZrB2 was analyzed.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2004年第4期507-511,523,共6页
Journal of The Chinese Ceramic Society
基金
山东省优秀中青年科学家奖励基金(2000)
山东省科委高新技术基金(GXB991)资助项目。~~
关键词
硼化镧-硼化锫复合粉末
热压烧结
复合材料
力学性能
Bending strength
Borides
Carbon
Crystal microstructure
Fracture toughness
Hardness
Hot pressing
Lanthanum compounds
Morphology
Polycrystalline materials
Reduction
Scanning electron microscopy
Sintering
Zirconium compounds
