铁基触媒中的初生渗碳体与金刚石单晶的合成  

Relationship of Original Cementite in Iron - based Catalyst and Synthesis of Diamond Monocrystal

作　　者：崔建军[1] 许斌[2] 李木森[1] 尹龙卫[1] 宫建红[1] 李洪岩[1] 

机构地区：[1]山东大学材料科学与工程学院 [2]山东建筑工程学院材料科学与工程学院,济南250061

出　　处：《金刚石与磨料磨具工程》2005年第2期1-3,6,共4页Diamond & Abrasives Engineering

基　　金：国家自然科学基金资助项目(50371048和50372035)

摘　　要：本文利用光学显微镜、扫描电镜和X射线衍射仪研究了金刚石合成后的铁基触媒组织结构。结果表明,组织中有较多的初生渗碳体时,金刚石的质量好,产量高;反之,则质量差,数量少。分析表明:触媒从高温液态到室温固态经历了初生渗碳体的析出、长大和共晶凝固两个过程,高温高压下金刚石的形核与长大是在触媒熔液经历初生渗碳体阶段时形成的。金刚石的生长极有可能是通过初生渗碳体的分解实现的,碳原子集团从渗碳体脱溶,然后堆积到金刚石上。本文从冶金反应过程证明了金刚石是由初生渗碳体转变而来的。Optics Microscope, scanning electron microscope ( SEM ) and X - ray diffraction ( XRD) methods were used to investigate the structure of synthesized iron - based catalyst. The results showed that more original cementite in catalyst at room temperature and atmosphere pressure corresponds to better quality and higher yield of diamond, whereas poor quality and lower yield of diamond corresponds to less original cementite in it. The diamond formation and growth may accompany with the original cementite formation in the molten catalyst at high temperature and high pressure (HPHT) , and carbon atoms for diamond growth may be from the separation of the original cementite in the molten catalyst. The carbon atom groups separate from cementite, and then accumulate on the growing diamond crystals. According to metallurgy principle, it can be also demonstrated that the diamond formation and growth come from the original cementite in the molten catalyst.

关 键 词：铁基触媒 高温高压 金刚石合成 初生渗碳体 

分 类 号：TQ164[化学工程—高温制品工业]