B4C/石墨复合粉体的合成及抗氧化性能  

SYNTHESIS AND ANTI-OXIDANT PROPERTIES OF B_4C/GRAPHITE COMPOSITE POWDERS

作　　者：李享成[1] 周芬[1] 朱伯铨[1] 

机构地区：[1]武汉科技大学,耐火材料与高温陶瓷国家重点实验室培育基地,武汉430081

出　　处：《硅酸盐学报》2010年第6期1070-1074,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50904048)资助项目

摘　　要：用聚乙烯醇[poly(vinyl alcohol),PVA]、硼酸合成B4C/石墨复合粉体。通过红外光谱,X射线衍射仪及扫描电子显微镜分析复合粉体的显微结构。研究发现:硼酸与PVA形成凝胶,在700℃煅烧2h后生成中间产物B-O-C。中间产物在埋碳气氛下煅烧,只生成石墨而没有B4C;在Ar气氛中于1300℃煅烧5h,能够形成B4C和石墨。加入碳黑有助于合成B4C。合成的B4C颗粒尺寸在1μm以下,石墨的粒度为2～3μm,B4C依附于石墨表面生长。将B4C/石墨复合粉体作为碳源加入Al2O3材料中,在空气中于1200℃煅烧2h后作抗氧化实验。结果表明:氧化层厚度为4.09mm,原始层面积保持在60%以上,显示出抗氧化性能。Boron carbide/graphite composite powder was synthesized using poly（vinyl alcohol） （PVA） and boric acid as raw materials. The composite powder was characterized by the Fourier transform infrared spectra,X-ray diffraction and scanning electron micro-scope. The results show that mixed solution of the PVA and boric acid can be dried to form gel and then generate intermediate of B—O—C calcined at 700 ℃ for 2 h in air. When the intermediate is calcined in reducing atmosphere,the graphite can be formed but B4C can not exist. The boron carbide/graphite composite powders are synthesized from the intermediate in Ar atmosphere at 1 300 ℃ for 5 h. What is more,the addition of carbon black can improve the synthesis of B4C. The particle size of B4C is below 1 μm while that of the graphite is 2–3μm. The B4C phase exists on surface of the graphite. The boron carbide/graphite is introduced into Al2O3 materials as carbon resource. The oxidant experiments in air at 1 200 ℃ for 2 h show that the thickness of oxide layer is 4.09 mm and the percent area of non-oxidant layer is above 60%. The boron carbide/graphite composite powders possess the anti-oxidant properties.

关 键 词：碳化硼/石墨 合成 抗氧化性 气氛 

分 类 号：TQ175.13[化学工程—硅酸盐工业]