六方BN陶瓷的高压气-固自蔓延高温合成

来源期刊：中国有色金属学报1999年第3期

论文作者：陈贵清 韩杰才 张宇民 杜善义

文章页码：526 - 530

关键词：h-BN陶瓷；高压；气-固反应； SHS

Key words：h-BN ceramics; high pressure; gas-solid reactions; SHS

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/cm^-3的六方BN(h-BN)陶瓷，其最高抗弯强度和硬度分别为42.8MPa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h-BN陶瓷产物，其范围为：48%≤ρ≤52%，95 MPa≤p≤110MPa。同时发现产物中的片状h-BN颗粒为各向同性，h-BN产物纯度较高，在高的氮气压力条件下合成的h-BN颗粒较大。片状h-BN颗粒内部出现分裂和弯折等现象。

Abstract: 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, 4 8%≤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.