(哈爾濱工業(yè)大學(xué)復(fù)合材料研究所，哈爾濱 150001)
摘 要: 采用高壓氣-固自蔓延高溫合成技術(shù)制備了產(chǎn)物密度為1.70 g/cm-3的六方BN(h-BN)陶瓷，其最高抗彎強(qiáng)度和硬度分別為42.8MPa和108(HV)；分析了氮?dú)鈮毫统跏伎紫堵蕦?duì)反應(yīng)物點(diǎn)燃和產(chǎn)物的影響，發(fā)現(xiàn)在適當(dāng)?shù)某跏伎紫堵屎偷獨(dú)鈮毫l件下，可以合成沒有裂紋的h-BN陶瓷產(chǎn)物，其范圍為：48%≤ρ≤52%，95 MPa≤p≤110MPa。同時(shí)發(fā)現(xiàn)產(chǎn)物中的片狀h-BN顆粒為各向同性，h-BN產(chǎn)物純度較高，在高的氮?dú)鈮毫l件下合成的h-BN顆粒較大。片狀h-BN顆粒內(nèi)部出現(xiàn)分裂和彎折等現(xiàn)象。
關(guān)鍵字: h-BN陶瓷；高壓；氣-固反應(yīng)； SHS
（Center for Composite Materials, Harbin Institute of Technology, Harbin 150001,P.R.China）
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.
Key words: h-BN ceramics; high pressure; gas-solid reactions; SHS
