碳源石墨结构对金刚石合成的影响

Effects of Structure of Graphite as Carbon Source on Synthesis of Diamond

借助于X射线衍射和扫描电镜 ,研究了 6种碳源石墨的晶体结构与显微结构。结果表明 ,不同石墨的颗粒度粗细不一 ,且石墨化度差异较大 ,微晶尺寸与石墨化度没有直接关系 ;石墨微观结构主要有 3种形态 :①纤维状区域结构 ;②片状小区域结构 ;③镶嵌结构合成金刚石时 ,微观结构相似的石墨 ,随着石墨化度的提高 ,加热电流增加 ;纤维状区域结构明显的石墨合成的金刚石品质优于片状小区域结构为特征的石墨 。

The crystal structures and microstructures of six kinds of graphites as carbon source were studied by X ray diffraction and scanning electron microscope. The results show that various graphites with different grain sizes differd much in their graphitization degree, the microcrystal sizes had no direct effect on the graphitization of the graphite. The microstructure of graphite exhibited three forms such as fibrous region structure, flake small region structure and mosaic structure. In synthesis of diamond, the heating current of graphites with similar microstructures increased with their graphitization degree. The diamonds synthesized with obvious fibrous region structural graphite had better quality than with the flake small region structural or mosaic structural graphite.