Investigation of Microstructure and Thermal Shock Resistance of the B4C/BN Composites Fabricated by Hot-pressing Process
The B4C/BN microcomposites were fabricated by hot-pressing process,and the B4C/BN nanocomposites were fabricated by chemical reaction and hot-pressing process.The phase composition,microstructure,mechanical property and thermal shock resistance of the microcomposites and nanocomposites were investigated.Both composites exhibited the homogenous and compact microstructure,and the h-BN particles were homogenously distributed in the B4C matrix.The mechanical property of the microcomposites and nanocomposites decreased gradually with the increase of h-BN content,but the nanocomposites exhibited the higher mechanical property than that of the microcomposites.The thermal shock resistances of the B4C monolith and the composites were measured by water-quenching method.The thermal shock resistances of the microcomposites and the nanocomposites were remarkably improved in comparison with the monolith.The thermal shock resistance of the nanocomposites was much better than that of the microcomposites.The thermal shock temperature difference (△Tc) of the B4C monolith was about 300℃,the △Tc of the microcomposites was about 500℃ and the △Tc of the nanocomposites was about 600℃.The B4C/BN composites exhibited the high thermal shock resistance due to the high fracture strength and low elastic modulus.The microstructure showed that the weak interface of B4C/BN and cleavage behavior of laminate structured h-BN particles would remarkably improve the thermal shock resistance of the B4C/BN composites.
B4C/BN composites Microstructure Thermal shock resistance Hot-pressing process
Tao Jiang Chenchao Tian
School of Materials Science and Engineering,Xian Shiyou University,Xian 710065,Peoples Republic of China
国际会议
The Seventh China International Conference on High-Performance Ceramics (第七届先进陶瓷国际研讨会(CICC-7))
厦门
英文
748-752
2011-11-04（万方平台首次上网日期，不代表论文的发表时间）