摘要
采用高压气固自蔓延高温合成技术制备了产物密度为1 .70 g/cm3 的六方BN(hBN) 陶瓷,其最高抗弯强度和硬度分别为42 .8 MPa 和108(HV) ; 分析了氮气压力和初始孔隙率对反应物点燃和产物的影响, 发现在适当的初始孔隙率和氮气压力条件下, 可以合成没有裂纹的hBN 陶瓷产物, 其范围为:48 % ≤ρ≤52 % ,95 MPa ≤p ≤110 MPa。同时发现产物中的片状hBN 颗粒为各向同性,hBN 产物纯度较高, 在高的氮气压力条件下合成的hBN 颗粒较大。片状hBN
h BN ceramics were prepared from powders of B and h BN by means of high pressure gas solid self propagating high temperature synthesis technology. The density of h BN ceramics is 1.70 g/cm 3, the bending strength and the hardness of h BN ceramics were 42.8 MPa and 108(HV) respectively. The nitrogen pressure and porosity of reactants that influence ignition and products have a best scope, 95 MPa≤ p ≤110 MPa, 48%≤ ρ ≤52%, in which the steady combustion products can be obtained. By X ray diffraction, scanning electron microscopy and transmission electron microscopy, the phase and microstructure were analyzed. The higher the nitrogen pressure, the larger the h BN particle. The distribution of h BN particles is anisotropic. There are branches and twists in the h BN particles.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
1999年第3期526-530,共5页
The Chinese Journal of Nonferrous Metals