掺硼细颗粒金刚石高温高压合成与研究

【作者】 张和民；

【导师】 贾晓鹏；

【作者基本信息】 河南理工大学 ， 矿物加工工程， 2009， 硕士

【摘要】 金刚石是超硬材料的代表性产品,具有许多优越的物理、化学性质,是一种极限功能材料。它被广泛地应用于工业、科技、国防、医疗卫生等领域,在促进工业发展方面起着举足轻重的作用。我国不是天然金刚石盛产国,因此独立地掌握高水平的金刚石合成技术是具有战略意义的。本文以合成金刚石的溶剂理论为指导,借鉴金刚石合成的一般规律,并根据国产六面顶压机的特点和铁基粉末触媒的特性,从组装设计到工艺调整均进行了科学合理的改进,找到了铁基粉末触媒合成高品级优质细颗粒（200—300目）金刚石单晶的工艺条件和方法,并在此基础上,研究了Fe₈₀Ni₂₀+C的体系和Fe₇₀Ni₃₀+C体系中添加硼粉对合成细颗粒金刚石条件的影响,考察了硼对细颗粒金刚石晶体的宏观特征（颜色、晶形和包裹体等）以及晶体表面形貌的改变。研究结果表明:随着硼添加量的增加,使得粉末触媒合成金刚石的合成温度和压力条件呈动态变化,先降低后升高,以及（100）和（111）晶面的生长区间发生改变。硼添加量较高时影响晶体生长的完整性,（100）晶面多出现圆形或椭圆形凹坑而（111）晶面多出现三角形凹坑。借助于扫描电子显微镜（SEM）观察到了金刚石表面的生长纹路,以及晶体表面形成的孔洞缺陷,并借助XRD衍射谱和拉曼光谱表征了硼对金刚石特征峰的变化。更多还原

【Abstract】 Diamond is a representative production of superhard materials. It is a limiting functional material with many exceptional physical and chemical properties. Now, it has been applied in many fields such as industry, scientific research, national defense, medical treatment etc. Diamond plays an important part in the development of industry. China is not rich in natural diamond, so that independently holding high-level diamond synthesis technique is of realistic strategic significance.In this paper, using the solvent theory of sythesizing diamond as the guiding ideology and learning ideas from the general rules of synthetic diamond, according to the traits of Cubic anvil apparatus and the characteristics of iron-based catalyst powder,the technology and mathods of synthesizing high quality fine-grained (200-300 mesh)single-crystal diamond is finally found using iron-based powder catalyst through improving scientifically and rationally designing assembly as well as adjusting process. On that basis, the impacts of synthesizing fine-grained diamond was researched in the Fe80Ni20 + C system and Fe70Ni30 + C system added boron powder. The impacts of synthesizing condition, macro-characteristics (color, shape and inclusion, etc.) as well as the changes of crystal surface morphology were studied. The results show that: With the addition of boron, the conditon of temperature and pressure synthesizing diamond with powder catalyst took on dynamic changes and the growth rigion of (100) and (111) crystal plane was changed. With high boron added, the integrity of crystal was affected, (100) crystal plane appeared more round or oval pits and (111) crystal plane appeared more triangular pits. With scanning electron microscopy (SEM) , growth patterns on the surface of the diamond as well as the hole and defects on the surface of crystals were observed. Using XRD diffraction and Raman spectroscopy , the changes of diamond’s characteristic peaks were described.更多还原