Dislocations, Plasticity, and Strain Hardening in Carbon Nanotubes

碳纳米管中的位错、塑性和应变硬化

• 批准号: 0528511
• 负责人: Daryl Chrzan
• 金额: --
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0528511&HistoricalAwards=false
• 关键词: Dislocations; Plasticity; Strain; Hardening; Carbon

Dislocations, Plasticity, an Strain Hardening in Carbon NanotubesD. C. ChrzanDepartment of Materials Science and EngineeringUniversity of CaliforniaBerkeley, CA 94720-1760AbstractCarbon nanotubes display unusually high tensile strengths and stiffnesses, and breaking stresses as high as 30 GPa have been reported. While the elastic properties of carbon nanotubes are well understood, the plastic properties of carbon nanotubes remain unsettled. Intriguingly, carbon nanotubes are expected to deform plastically through the nucleation of dislocation dipoles (Stone-Wales defects), the dissociation of these dipoles, and the subsequent motion of the dislocations. Estimates of the formation energy for Stone-Wales defects vary widely, perhaps because their formation energy is influenced by elastic interactions between the defects. We will use elasticity theory solutions for periodic dislocation arrays to analyze defect formation energies obtained from density functional theory based total energy methods. This analysis will yield core radii for the dislocations and ultimately, a transferable theory of dislocations in nanotubes. This theory can then be applied to model plasticity in carbon nanotubes under a variety of loading conditions.

位错，可塑性，碳纳米管中的应变硬化。 C. Cliforniaberkeley材料科学和工程学的Chrzandepartment，CA 94720-1760abtractcarcarcartcarcarcorbactarcarcarbactercarnotubes表现出异常高的拉伸强度和刚度，据报道，已经报道了高达30 GPA的压力。虽然碳纳米管的弹性特性众所周知，但碳纳米管的塑性特性仍未确定。有趣的是，碳纳米管有望通过脱位偶极子（石 - 孔缺陷），这些偶极子的离解和脱位的随后运动的含量塑料变形。 石 - 孔缺陷的地层能量的估计值差异很大，也许是因为它们的形成能受到缺陷之间的弹性相互作用的影响。我们将使用弹性理论解决方案进行周期性错位阵列来分析从基于密度功能理论的总能量方法获得的缺陷形成能。 该分析将产生核心半径，最终是纳米管中可转移的位错理论。 然后，该理论可以应用于在各种载荷条件下的碳纳米管中的可塑性。