Atomistic behavior of nanoporous carbon nanotube-aluminum composite under compressive loading

ME Suk, MATERIALS RESEARCH EXPRESS, 7, 015028 (2020).

DOI: 10.1088/2053-1591/ab6092

Metal matrix nanocomposites have been actively studied to discover the characteristics of a new class of materials. In the present study, metal matrix nanocomposites are investigated using molecular dynamics simulations of the compressive behavior of nanoporous carbon nanotube (CNT)-aluminum (Al) composites that have a density of approximately 77% to that of pure Al. The weight-reduced nanocomposites exhibited an enhanced Young's modulus of 138%, and a compressive strength degraded by 13% compared with pure Al. Through stress decomposition into CNT and Al constituents, it was observed that the Young's modulus was enhanced due to the high stiffness of the CNTs; further, the reduced strength was primarily due to the early failure strain. The effects of CNT volume fractions and sizes are further analyzed using the rule of mixture, which is modified by the interphase area definition. In addition, the atomistic details of the structure and stress revealed a buckling behavior in the CNT as well as a massive slip behavior in the Al matrix during plastic deformation. The results presented in this study will have implications in the design and development of metal matrix nanocomposites for applications in high-performance lightweight materials.

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