Phase evolution and dielectric property of LPCVD/CVI-SiBCN annealed at different temperatures
The SiBCN ceramics with amorphous microstructure were introduced to porous Si3N4 ceramics at 800oC via Low-pressure chemical vapor deposition and infiltration(LPCVD/CVI), and then the composite ceramics were heat-treated at 1400-1700oC in N2 atmosphere.Effects of annealing temperature on microstructure, phase evolution, dielectric property of SiBCN were investigated.The results revealed that α-Si3N4 and free carbon were separated before 1700oC, and then SiC grains which had excellent wave-absorbing property were formed after annealing at 1700oC through the phase-reaction between free carbon and α-Si3N4.The average dielectric loss of composites increased to 0.03 from 0 due to the formation of dispersive SiC grains and increased grain boundary, indicating the annealed SiBCN ceramics had certain EM wave absorbing properties.
Chemical vapor deposition/infiltration SiBCN Crystallization Dielectric properties
Mingxi Zhao Yongsheng Liu Nan Chai Hailong Qin Xiaofei Liu Fang Ye Laifei Cheng Litong Zhang
Science and technology on Thermostructure Composite Materials Laboratory,Northwestern Polytechnical State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi”an,Shaanx
国内会议
长沙
英文
284-289
2016-11-11（万方平台首次上网日期，不代表论文的发表时间）