A quantitative relationship between grain size and Young's modulus of metal composites has not been established by considering the coupling effect of the reinforcements on microstructural deformation.The objective...A quantitative relationship between grain size and Young's modulus of metal composites has not been established by considering the coupling effect of the reinforcements on microstructural deformation.The objective of this study is to investigate the mechanism of deformation coordination between the carbon nanotube and the composite microstructure using molecular dynamics simulations.Through the analysis of stress contributions from grain boundaries and grains,a grain size-dependent continuum model for the pure metal modulus is established.On this basis,a predictive model for the modulus of metallic composites is developed by considering the coupling deformation between carbon nanotubes and the grains.The proposed model is capable of accurately capturing the relationship between grain size and the modulus of metal composites.This study provides a guideline for microstructure-dependent multiscale modeling.展开更多
It is a crucial requirement for structure-damping materials to attain both stiffness and damping;unfortunately,the two properties are usually mutually exclusive.This study interestingly demonstrates that introducing N...It is a crucial requirement for structure-damping materials to attain both stiffness and damping;unfortunately,the two properties are usually mutually exclusive.This study interestingly demonstrates that introducing Ni atoms into the interface of carbon nanotube(CNT)reinforced aluminum-matrix composites can defeat the conflict of stiffness versus damping.This originates from the gradient variation of the modulus and energy dissipation in the effective interfacial zone.The rule of mixture is modified by taking the interface contribution into account,and a gradient damping model is proposed to account for the contribution of the interface energy dissipation.Molecular dynamics simulations confirm that the proposed multiscale modulus and damping models can describe the elastic modulus and damping behavior of the composites with different volume fractions and different diameters of CNTS.The gradient interface slip caused by the lattice mismatches and misfit dislocations between Ni-coated CNT and aluminum is one of the pathways for achieving unprecedented levels of the product of stiffness and damping.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52175095)the Key Research and Development Program of Guangxi of China(Grant No.GuikeAB23026106)the Young Topnotch Talent Cultivation Program of Hubei Province of China。
文摘A quantitative relationship between grain size and Young's modulus of metal composites has not been established by considering the coupling effect of the reinforcements on microstructural deformation.The objective of this study is to investigate the mechanism of deformation coordination between the carbon nanotube and the composite microstructure using molecular dynamics simulations.Through the analysis of stress contributions from grain boundaries and grains,a grain size-dependent continuum model for the pure metal modulus is established.On this basis,a predictive model for the modulus of metallic composites is developed by considering the coupling deformation between carbon nanotubes and the grains.The proposed model is capable of accurately capturing the relationship between grain size and the modulus of metal composites.This study provides a guideline for microstructure-dependent multiscale modeling.
基金supported by the National Natural Science Foundation of China(Grant Nos.52175095 and 51605172)the Young Top-notch Talent Cultivation Program of Hubei Province of China。
文摘It is a crucial requirement for structure-damping materials to attain both stiffness and damping;unfortunately,the two properties are usually mutually exclusive.This study interestingly demonstrates that introducing Ni atoms into the interface of carbon nanotube(CNT)reinforced aluminum-matrix composites can defeat the conflict of stiffness versus damping.This originates from the gradient variation of the modulus and energy dissipation in the effective interfacial zone.The rule of mixture is modified by taking the interface contribution into account,and a gradient damping model is proposed to account for the contribution of the interface energy dissipation.Molecular dynamics simulations confirm that the proposed multiscale modulus and damping models can describe the elastic modulus and damping behavior of the composites with different volume fractions and different diameters of CNTS.The gradient interface slip caused by the lattice mismatches and misfit dislocations between Ni-coated CNT and aluminum is one of the pathways for achieving unprecedented levels of the product of stiffness and damping.
