Enhanced interface interaction between modified carbon nanotubes and magnesium matrix

Abstract

Carbon nanotube (CNT)/metal interface interaction is critical to the mechanical properties of CNT-reinforced metal matrix composites (MMCs). In this paper, in order to realize the chemical modification of the interface interaction between CNTs and Mg matrix, different types of defects (monovacancy, carbon and oxygen adatoms, as well as p-type boron and n-type nitrogen substitution) are introduced in CNTs to investigate the effect of the defects on the interface interaction (E _ib) between CNT and Mg (0 0 0 1) surface. Moreover, two models (adsorption model and interface model) are compared and validated to investigate the interface interaction. It is revealed that the CNT with the carbon adatom has the highest E _ib with the Mg (0 0 0 1), and the effect of boron doping on E _ib is superior to the intermediate oxygen which has already been proved experimentally in the enhancement of the interface interaction in MMCs. In terms of the electronic structure analysis, we reveal the micro-mechanism of the increase of E _ib under the action of different types of defects, and propose that the presence of holes (boron dopant) and the unsaturated electrons in CNTs can generate the chemical interaction between CNT and Mg matrix effectively. Our results are of great scientific importance to the realization of robust interfacial bonding between CNTs and Mg matrix via the reinforcement modification, so as to enhance the mechanical properties of CNTs reinforced Mg matrix composites.

Keywords:

• Density functional calculations
• CNT/Mg composites
• interfacial bonding
• defects

Supplemental data

The supplemental data for this article can be accessed at https://doi.org/10.1080/09276440.2018.1460142.

Funding

This work was supported by the financial support by National Key R&D Program of China [grant number 2017YFB0703101]. The work was carried out at National Supercomputer Center in Tianjin, and the calculations were performed on TianHe-1(A).

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgement

The authors acknowledge the financial support by National Key R&D Program of China (Grant No. 2017YFB0703101). The work was carried out at National Supercomputer Center in Tianjin, and the calculations were performed on TianHe-1(A).