含缺陷双层石墨烯的纳米压痕模拟研究

发布时间：2018-01-05 03:24

本文关键词：含缺陷双层石墨烯的纳米压痕模拟研究　出处：《力学学报》2016年04期 　论文类型：期刊论文

【摘要】：石墨烯具有独特的力学、电学性能,被誉为是具有战略意义的新材料,具有广泛的应用前景.目前生产的石墨烯含有各种缺陷,相较于完美石墨烯,其仍有较大应用价值.因此有必要研究和掌握缺陷对石墨烯性能的影响,以便在目前的生产技术下,推动其工业化应用.采用Tersoff势来模拟C—C共价键的相互作用,Lernnard--Jones势来模拟非成键碳原子之间相互作用力,基于分子动力学模拟了金刚石压头压入含缺陷双层石墨烯的纳米压痕过程,讨论了Lernnard--Jones势函数的截断半径最佳值以及得到了典型的载荷-位移曲线.重点探讨了Stone--Thrower--Wales、空位(包括单空位和双空位缺陷)以及圆孔缺陷当位置不同和数目不同时对石墨烯力学性能的影响.得出结论:薄膜中心存在缺陷时,破坏强度下降幅度特别明显.空位缺陷在压头半径范围内存在时,临界载荷与缺陷与薄膜中心的距离成线性关系;缺陷数目越多,其杨氏模量、破坏强度等就越低.圆孔缺陷数目在压头范围外达到一定浓度后会使石墨烯的力学性质显著降低.本文结论也说明石墨烯结构稳定,对小缺陷不敏感,缺陷石墨烯仍具有较好的性能和使用价值.
[Abstract]:Graphene has unique mechanical and electrical properties, has been hailed as the new material with strategic significance, has broad application prospects. At present, containing a variety of defects in the graphene production, compared with the perfect graphene, it still has greater application value. So it is necessary to study and master the defect effect on graphene properties. So in the current production technology, to promote the industrial application. The interaction of Tersoff potential is used to simulate the C - C bond, Lernnard--Jones potential to simulate the interaction between the non bonded carbon atoms, based on molecular dynamics simulation of the diamond indenter nanoindentation process containing defects in bilayer graphene, discussed the best the value of truncation radius Lernnard--Jones potential function and the typical load displacement curve. Focusing on the Stone--Thrower--Wales vacancy (including single and double vacancies) and short hole When the depression effect of different position and number on the mechanical properties of graphene. The conclusion is that there is defect film center, failure strength decline is particularly evident. In the presence of indenter radius vacancy, critical load and film defects and the distance from the center of the linear relationship between the number of defects; more, the young's modulus damage strength is lower. The number of defect reaches a certain concentration in the head range will make the mechanical properties of graphene was significantly reduced. This conclusion also shows that the graphene structure is stable, not sensitive to small defects, defects in the graphene has good performance and use value.

【作者单位】：西安建筑科技大学理学院力学系;
【基金】：西安建筑科技大学校人才科技基金资助项目(DB12062)
【分类号】：O613.71
【正文快照】： region covered by indenter radius which makes the mechanical properties of graphene decrease apparently.It is concludedthat graphene with the stable structure is not sensitive to small defects and defective graphene still has good performanceand practica

【相似文献】