• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2015, Vol. 51 ›› Issue (17): 162-168.doi: 10.3901/JME.2015.17.162

• 制造工艺与装备 • 上一篇    下一篇

铁基作用下的金刚石石墨化研究

郭晓光,翟昌恒,金洙吉,郭东明   

  1. 大连理工大学精密与特种加工教育部重点试验室
  • 出版日期:2015-09-05 发布日期:2015-09-05
  • 基金资助:
    国家重点基础研究发展(973计划,2011CB706704)、创新研究群体科学基金(51321004)和高等学校博士学科点专项科研基金(20120041110035)资助项目

The Study of Diamond Graphitization under the Action of Iron-based Catalyst

GUO Xiaoguang, ZHAI Changheng, JIN Zhuji, GUO Dongming   

  1. Key Laboratory for Precision and Non-traditional Machining of Ministry of Education, Dalian University of Technology
  • Online:2015-09-05 Published:2015-09-05

摘要: 通过构建含催化剂铁的金刚石仿真模型,进行了金刚石石墨化的三维分子动力学仿真,获得了金刚石在铁基催化剂作用下的石墨化机理。并对化学气相沉积金刚石进行了摩擦化学抛光试验,验证了铁基金属对金刚石石墨化的催化作用。分子动力学仿真结果表明铁原子的存在会降低金刚石石墨化的转变温度,进一步的微观结构分析可以得出,在催化剂作用下的石墨化机理是:铁原子价电子层中的未配对电子与金刚石原子的电子相互作用,形成了化学键,对金刚石原子产生吸引作用,使其逐渐变为石墨结构。所以铁基催化剂具有催化作用的原因就是铁原子价电子层结构中含有未配对的电子,而且与金刚石原子结构符合对准原则。试验结果验证了仿真结论的正确性。研究结果表明,金属铁的存在会加速金刚石石墨化的过程,利于对金刚石刀具的超精密加工。

关键词: 催化作用, 分子动力学, 金刚石, 石墨化

Abstract: In order to get the graphitization mechanism of diamond under the action of iron-based catalyst, a three-dimensional molecular dynamics (MD) simulation is performed on a particular model containing iron and diamond atoms. And the friction chemical polishing experiments for the chemical vapor deposition (CVD) diamond is conducted to validate the catalytic action of the iron-based metal on diamond graphitization. The results of molecular dynamics simulation show that the presence of iron atoms will reduce the transformation temperature of diamond graphitization. By analyzing the microstructure, the graphitization mechanism with catalyst can be concluded that the chemical bonds are formed by the interaction between the unpaired electrons in the valence shell of iron atoms and the electrons of diamond atoms, which will attract the diamond atoms and make them become graphite structure gradually. For the mechanism of the catalysis of iron for diamond graphitization, there are two critical reasons. On one hand, there are unpaired electrons in the valence shell of the catalytic metal atoms. On the other hand, the structures of the catalytic metal and the diamond conform to the principle of alignment. The experimental results further validate the correctness of the simulation conclusion. Therefore it is concluded that the presence of iron will accelerate the process of diamond graphitization, which is good for the ultra-precision machining of diamond tools.

Key words: catalysis, diamond, graphitization, molecular dynamics

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