Carneiro Íris, Simões Sónia
DEMM, Department of Metallurgical and Materials Engineering, University of Porto, R. Roberto Frias, 4200-465 Porto, Portugal.
LAETA/INEGI-Institute of Science and Innovation in Mechanical and Industrial Engineering, R. Roberto Frias, 4200-465 Porto, Portugal.
Materials (Basel). 2020 Dec 6;13(23):5557. doi: 10.3390/ma13235557.
The effect of using different carbon nanotubes (CNTs) on the production of nanocomposites was evaluated in this work. The investigated CNTs were multi-walled carbon nanotubes (MWCNTs) with different morphologies and structures. The main objective was to relate the results reported by numerical simulation with the results obtained experimentally in order to validate these methodologies. A detailed characterization of CNTs was carried out to establish the different main characteristics, such as inner and outer diameters, defects, structure and the number of walls. Metal matrix nanocomposites were produced using the powder metallurgy route. The experimental results show that the morphology and structure of MWCNTs have a significant effect on the dispersion process for nanocomposite production. Straight CNTs with a larger diameter and with few defects allow for the production of nanocomposites with uniform dispersion and strong interface bonding, leading to a higher hardness value. In addition, the CNT introduction into a metal matrix induces a change in the deformation behavior that plays an important role in the strengthening mechanisms. Although some aspects are not considered in the molecular dynamic (MD) simulation, such as the CNT random orientation and CNT agglomeration, some comparative relationships can be performed in order to validate some methodologies. While the structure and morphology of the CNTs have a significant influence on the dispersion process, the influence of the diameter and the functionalization treatment on the properties of the nanocomposites is also identified. The experimental results show that the decrease in the diameter of the CNTs and the use of functionalized CNTs also contribute to the obtention of lower mechanical properties of the nanocomposites, as is pointed out in the results of MD carried out in nanocomposites.
本工作评估了使用不同碳纳米管（CNT）对纳米复合材料生产的影响。所研究的碳纳米管为具有不同形态和结构的多壁碳纳米管（MWCNT）。主要目的是将数值模拟报告的结果与实验获得的结果相关联，以验证这些方法。对碳纳米管进行了详细表征，以确定其不同的主要特征，如内径和外径、缺陷、结构和壁数。采用粉末冶金路线制备金属基纳米复合材料。实验结果表明，多壁碳纳米管的形态和结构对纳米复合材料生产的分散过程有显著影响。直径较大且缺陷较少的直碳纳米管能够生产出具有均匀分散和强界面结合的纳米复合材料，从而获得更高的硬度值。此外，将碳纳米管引入金属基体中会引起变形行为的变化，这在强化机制中起着重要作用。尽管分子动力学（MD）模拟未考虑某些方面，如碳纳米管的随机取向和碳纳米管团聚，但仍可进行一些比较关系以验证某些方法。虽然碳纳米管的结构和形态对分散过程有显著影响，但也确定了直径和功能化处理对纳米复合材料性能的影响。实验结果表明，碳纳米管直径的减小和功能化碳纳米管的使用也有助于获得力学性能较低的纳米复合材料，如在纳米复合材料中进行的分子动力学结果所指出的那样。
