Suk Myung Eun
Mechanical Engineering, IT Convergence College of Materials and Components Engineering, Dong-Eui University, Busan 614-714, Korea.
Molecules. 2021 Jun 28;26(13):3947. doi: 10.3390/molecules26133947.
By using the advantages of carbon nanotubes (CNTs), such as their excellent mechanical properties and low density, CNT-reinforced metal matrix composites (MMCs) are expected to overcome the limitations of conventional metal materials, i.e., their high density and low ductility. To understand the behavior of composite materials, it is necessary to observe the behavior at the molecular level and to understand the effect of various factors, such as the radius and content of CNTs. Therefore, in this study, the effect of the CNT radius and content on the mechanical properties of CNT-Al composites was observed using a series of molecular dynamics simulations, particularly focusing on MMCs with a high CNT content and large CNT diameter. The mechanical properties, such as the strength and stiffness, were increased with an increasing CNT radius. As the CNT content increased, the strength and stiffness increased; however, the fracture strain was not affected. The behavior of double-walled carbon nanotubes (DWNTs) and single-walled carbon nanotubes (SWNTs) was compared through the decomposition of the stress-strain curve and observations of the atomic stress field. The fracture strain increased significantly for SWNT-Al as the tensile force was applied in the axial direction of the armchair CNTs. In the case of DWNTs, an early failure was initiated at the inner CNTs. In addition, the change in the elastic modulus according to the CNT content was predicted using the modified rule of mixture. This study is expected to be useful for the design and development of high-performance MMCs reinforced by CNTs.
通过利用碳纳米管（CNT）的优势，如优异的机械性能和低密度，碳纳米管增强金属基复合材料（MMC）有望克服传统金属材料的局限性，即高密度和低延展性。为了了解复合材料的行为，有必要在分子水平上观察其行为，并了解各种因素的影响，如碳纳米管的半径和含量。因此，在本研究中，使用一系列分子动力学模拟观察了碳纳米管半径和含量对碳纳米管-铝复合材料力学性能的影响，特别关注高碳纳米管含量和大碳纳米管直径的金属基复合材料。随着碳纳米管半径的增加，强度和刚度等力学性能也随之提高。随着碳纳米管含量的增加，强度和刚度增加；然而，断裂应变不受影响。通过应力-应变曲线的分解和原子应力场的观察，比较了双壁碳纳米管（DWNT）和单壁碳纳米管（SWNT）的行为。当在扶手椅型碳纳米管的轴向施加拉力时，SWNT-铝的断裂应变显著增加。在双壁碳纳米管的情况下，内部碳纳米管会提前发生失效。此外，使用修正的混合法则预测了弹性模量随碳纳米管含量的变化。本研究有望对碳纳米管增强高性能金属基复合材料 的设计和开发有所帮助。
