首页|碳纳米管增强镁基复合材料细观模型构建及力学响应

碳纳米管增强镁基复合材料细观模型构建及力学响应

Mesoscopic Model Construction and Mechanical Response of Carbon Nanotube Reinforced Magnesium Matrix Composites

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碳纳米管(CNTs)增强镁基复合材料的应力-应变响应预测对于理解可设计性参数在弹塑性变形阶段的影响具有重要意义.由于非均质材料有限元模拟的复杂性,在微尺度组分显式求解方面尚有一定的局限性.为获得非均质材料在弹塑性变形阶段中的宏观有效性质,基于改进的随机序列吸附算法建立了随机CNTs内嵌增强的镁基复合材料单胞物理模型,复合材料中的界面粘结层由内聚力单元代替,CNTs模型依据扫描电子显微镜(SEM)观测到的真实形貌建立.对三维数值模型进行有限元分析计算,求得表征体积单元数值模型有效性质的数值解,有效分析了拉伸载荷作用下材料基体破坏和界面脱粘、强度问题及各组成相间的应力传递机制、损伤机制.实验与模拟的对比结果表明,建立的复杂结构纳米相增强材料细观模型对于预测材料参数与细观结构、力学性能之间的响应关系能够提供客观、充分和真实的依据.
Carbon nanotubes(CNTs),as reinforced phase modified magnesium matrix composites,have become the focus of atten-tion in the large wingspan light unmanned air vehicle,new energy vehicles and intelligent medical equipment industries due to their unique thermophysical properties,mechanical properties,and process properties.The designable parameters such as distribution pat-tem,structure and content of CNTs in magnesium matrix have a great influence on the macroscopic mechanical properties of materials.The prediction of stress-strain response of carbon nanotube reinforced magnesium matrix composites is of great significance for under-standing the influence of designable parameters in the elastic-plastic deformation stage.However,the heterogeneous carbon nanotube reinforced magnesium matrix composites have high non-uniformity and complex structure,which makes the finite element modeling difficult and the calculation accuracy low.In view of this,in order to obtain the macroscopic effective properties of heterogeneous mate-rials in the elastic-plastic deformation stage,a representative volume element model(RVE)of composite materials embedded with ran-dom CNTs was established based on the improved random sequence adsorption algorithm.The interfacial bonding layer in the compos-ite material was replaced by the cohesive element.CNTs model in RVE model of the composites was based on the real morphology ob-served by the scanning electron microscope(SEM),and the content of CNTs was consistent with the experimental content.The com-posite RVE model was divided into periodic structured grids,and periodic boundary conditions were applied to ensure the stress conti-nuity and deformation coordination at the boundary of the composite RVE model.Considering the small thickness of the interface layer observed by the transmission electron microscope in the experiment,it could be simplified into a cohesive element grid of 0 thickness.The finite element analysis and calculation of the three-dimensional numerical model were carried out,and the numerical solution of the effective properties of the numerical model of the volume element was obtained.The damage of the material matrix and the interface debonding,the strength problem and the stress transfer mechanism and damage mechanism between the components under uniaxial tensile load were effectively analyzed.The comparison results of experiment and simulation showed that the meso-model of nano-phase reinforced composites with complex structure established in this paper could provide objective,sufficient and real basis for predicting the response relationship between material parameters and meso-structure and mechanical properties.CNTs reinforced Mg-6Zn com-posites used in this paper were prepared by ultrasonic-assisted semi-solid stirring casting.CNTs were pre-dispersed with mixed acid and acetone to prevent agglomeration.At the same time,it could also improve the wettability between CNTs and magnesium matrix,so that it had good interface bonding.The crystallization characteristics were characterized by JY HR800 micro Raman imaging spectrom-eter.The excitation source was He-Ne laser,the excitation wavelength was 514 nm,the wavelength was set to 532 nm,and the scan-ning time of CNTs was set to 300 s.Field emission SEM and Raman spectroscopy showed that CNTs were well bonded to the magne-sium matrix after pretreatment with mixed acid and acetone.

magnesium matrix compositescharacterizing volume unitsfinite element analysismacro effective properties

韩宝健、韩子文、应韬、郝振、李云帅、沈明杰

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陕西科技大学机电工程学院,陕西西安 710021

鞍钢集团钢铁研究院,辽宁鞍山 114003

上海交通大学材料科学与工程学院,上海 200240

镁基复合材料 表征体积单元 有限元分析 宏观有效性质

中国航天科技集团有限公司第八研究院产学研合作基金项目国家自然科学基金项目秦创原"科学家+工程师"队伍建设项目陕西高校青年创新团队(2024年)

USCAST2021-18517011082024QCY-KXJ-112

2024

10.13373/j.cnki.cjrm.XY23030040

稀有金属
北京有色金属研究总院

稀有金属

CSTPCD北大核心
影响因子：1.483
ISSN：0258-7076
年,卷(期)：2024.48(6)
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