Reinforcing Iron Metal Matrix Composite by Multi-Wall Carbon Nanotube: A Combined Theoretical and Computational Approach

TL;DR

This study combines theoretical modeling and molecular dynamics simulations to analyze how multi-wall carbon nanotube layer numbers affect the strength and failure mechanisms of iron matrix composites, aiding industrial application.

Contribution

It introduces a novel theoretical approach to predict composite properties based on MWCNT layers and validates it with MD simulations, revealing saturation points and failure initiation sites.

Findings

Strength increases by 9.8% per two layers up to eight layers.

Stiffness increases by 7.2% per two layers up to eight layers.

Failure initiates at grain boundaries, not the fiber-matrix interface.

Abstract

Carbon nanotube (CNT) reinforced metal matrix composites have been the focus of researchers due to their high load-bearing capacity. Among single and multi-wall carbon nanotubes (MWCNT), the latter is preferred by manufacturers and engineers for making composites due to their economic feasibility of synthesizing. However, the effect of layer numbers along with other parameters of the reinforcing MWCNT must be understood before its industrial application. In this article, we developed a novel theoretical approach for predicting the variation of strength and stiffness of MWCNT reinforced iron composites (MWCNT-Fe) with the layer number of reinforcing MWCNT and validated the prediction with a series of Molecular dynamics (MD) simulation. Our analysis revealed that for every addition of two extra layers, the strength and stiffness of the composite increase 9.8% and 7.2% respectively up to eight layered MWCNT and then becomes saturated. We also employed MD simulations for investigating the effect of grain boundary on the failure mechanism of CNT reinforced iron composites in contrast to previous studies. Our investigations revealed that instead of the matrix-fiber interface, the failure was initiated from the grain boundary and merges with the interface. The results in this study will not only help engineers and manufacturers choose optimal layered MWCNT for synthesizing composite for a specific application but also provide scientists a new method to model composites for predicting desired properties.