摘要
Molecular dynamics(MD)simulations of the titanium-graphene nanocomposites(TiGNCs)under uniaxial tension are carried out to investigate the mechanical properties and reinforcement mechanism of graphene in composites.It is found that introduction of mechanically robust graphene limits the strain-induced dislocation and araorphization and thereby highly improves the mechanical properties of metallic titanium that are greatly affected by the crystal stacking orientation of graphene and titanium layers.The thickness of titanium layers,interface interaction and working temperature play an important role in the mechanical strength and elastic moduli of composites.The results show the mechanical properties of TiGNCs are monotonically enhanced with reduction of the titanium layer thickness and working temperature,and the Young5s modulus obtained by MD simulation are higher than that predicted by the rule of mixture(ROM)due to consideration of interfacial interaction in computational calculation.In addition,once the critical thickness of titanium layer is reached,graphene wrinkles are induced in composites because of Poisson's effect induced large lateral compression stress in the interface region.This study provides helpful insights into fundamental understanding reinforcing mechanism of graphene and ultimately contribute to the optimal design and performance of mechanically robust graphene-based metallic composites.
基金
supported by the National Natural Science Foundation of China(Grants U1737106,51705411,11772278 and 11502221)
the Jiangxi Provincial Outstanding Young Talents Program(Grant 20192BCBL23029)
the Fundamental Research Funds for the Central Universities(Xiamen University:Grants 20720180014,20720180018 and 20720160088)
Shaanxi Provincial Natural Science Foundation(Grant 2018JM5022)
Fujian Provincial Department of Science&Technology(Grant 2017J05028)
“111”Project(Grant B16029)
the 1000 Talents Program from Xiamen University.
