A new micromechanical model of CNT-metal nanocomposites with random clustered distribution of CNTs

Chongyang Gao,Yu Lu,Y.T Zhu

doi:10.3221/igf-esis.33.52

Abstract

Uniform dispersion of carbon nanotubes (CNTs) is a key issue for utilization of their reinforcement potential in CNT-reinforced metal matrix nanocomposites (MMNCs). It was reported that CNT clusters often exist in MMNCs prepared by various techniques, which reduces the load transfer efficiency between the matrix and reinforcement. In this paper, a new micromechanical constitutive model of CNT-reinforced MMNCs is developed, which takes into account of the influences of CNT clusters and misorientations. The strength values of a CNT/Al nanocomposite predicted by the new model are compared first with experimental data for validation. Then, the developed model is applied to predict the size effect, temperature effect and strain rate effect of the nanocomposite in its overall elastoplastic response.

Highlights

In recent years, it has been reported that incorporating carbon nanotubes (CNTs) into polymers [1,2,3], ceramics and metals [4,5,6,7] can dramatically improve their mechanical properties
Yang et al [9] demonstrated that the yield strength of a 1.5 wt. % CNT/Al nanocomposite produced by an improved chemical vapor deposition (CVD) is 2.2 times that of the pure aluminum, while the result obtained in compression tests [10] is not so high due to different preparation technique of the sample
In the "Modelling of CNT-reinforced Metal matrix nanocomposites (MMNCs)" section, the cluster effect is introduced into the new model by using the statistically average equivalent length and diameter of CNTs, and the misorientation angle effect is reflected by a definition of an effective load transfer coefficient

Summary

Introduction

It has been reported that incorporating carbon nanotubes (CNTs) into polymers [1,2,3], ceramics and metals [4,5,6,7] can dramatically improve their mechanical properties. To describe the flow stress and estimate the plastic strength of CNT-reinforced metal matrix composites, a new micromechanical constitutive model, with consideration of the effect of CNT clusters and the influence of CNT misorientation angle, will be proposed in this paper.

Results

Conclusion