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Three-dimensional constitutive model for magneto-mechanical deformation of NiMnGa ferromagnetic shape memory alloy single crystals

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Acta Mechanica Sinica 2019年第3期35卷 563-588页

作者： Chao Yu Guozheng Kang Di Song xi xie state key {2. of Traction Power Southwest Jiaotong UniversityChengdu 610031China Applied Mechanics and Structure Safety key laboratory of Sichuan Province School of Mechanics and EngineeringSouthwest Jiaotong UniversityChengdu 610031China school of Mechatronics engineering University of Electronic Science and Technology of ChinaChengdu 610031China

Existing experimental results have shown that four types of physical mechanisms, namely, martensite transformation, martensite reorientation, magnetic domain wall motion and magnetization vector rotation, can be activated during the magneto-mechanical deformation of NiMnGa ferromagnetic shape memory alloy (FSMA) single crystals. In this work, based on irreversible thermodynamics, a three-dimensional (3D) single crystal constitutive model is constructed by considering the aforementioned four mechanisms simultaneously. Three types of internal variables, i.e., the volume fraction of each martensite variant, the volume fraction of magnetic domain in each variant and the deviation angle between the magnetization vector, and easy axis are introduced to characterize the magneto-mechanical state of the single crystals. The thermodynamic driving force of each mechanism and the thermodynamic constraints on the constitutive model are obtained from Clausius's dissipative inequality and constructed Gibbs free energy. Then, thermodynamically consistent kinetic equations for the four mechanisms are proposed, respectively. Finally, the ability of the proposed model to describe the magneto-mechanical deformation of NiMnGa FSMA single crystals is verified by comparing the predictions with corresponding experimental results. It is shown that the proposed model can quantitatively capture the main experimental phenomena. Further, the proposed model is used to predict the deformations of the single crystals under the non-proportional mechanical loading conditions.

关键词： Ferromagnetic shape memory alloys Single crystals Magneto-mechanical deformation Martensite transformation Martensite reorientation Constitutive model

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Compressive strain in Cu catalysts:Enhancing generation of C2.products in electrochemical CO_(2.reduction

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science Bulletin 2024年第18期69卷 2881-2891页

作者： Qikui Fan Pengxu Yan Fuzhu Liu Zhongshuang Xu Pengfei Liang xi Cao Chenliang Ye Moxuan Liu Lingyi Zhao Shan Ren Huanran Miao xiai Zhang Zhimao Yang xiangdong Ding Jian Yang Chuncai Kong Yuen Wu MOE key laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter Key Laboratory for Advanced Materials and Mesoscopic Physics of Shaanxi ProvinceSchool of PhysicsXi’an Jiaotong UniversityXi’an 710049China state key {2. for mechanical behavior of materials Xi’an Jiaotong UniversityXi’an 710049China College of Chemistry and materials science Anhui Normal UniversityWuhu 241002China Department of Power engineering North China Electric Power UniversityBeijing 102206China College of Chemistry and Chemical engineering Xi’an University of Science and TechnologyXi’an 710054China Center for materials and Interfaces Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Hefei National laboratory for Physical sciences at the Microscale Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)School of Chemistry and Materials Scienceand National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230026China

Elastic strain in Cu catalysts enhances their selectivity for the electrochemical CO_(2.reduction reaction(eCO_(2.RR),particularly toward the formation of multicarbon(C_(2.))***,the reasons for this selectivity and the effect of catalyst precursors have not yet been ***,we employed a redox strategy to induce strain on the surface of Cu *** transformation was employed to convert Cu nanocrystals to CuxO nanocrystals;these were subsequently electrochemically reduced to form Cu catalysts,while maintaining their compressive *** a flow cell configuration,a current density of 1 A/cm^(2.and Faradaic efficiency exceeding 80%were realized for the C_(2.)*** selectivity ratio of C_(2.)/C1 was also remarkable at 9.9,surpassing that observed for the Cu catalyst under tensile strain by approximately 7.6 ***-situ Raman and infrared spectroscopy revealed a decrease in the coverage of K+ion-hydrated water(K·H_(2.O)on the compressively strained Cu catalysts,consistent with molecular dynamics simulations and density functional theory *** element method simulations confirmed that reducing the coverage of coordinated K·H_(2.O water increased the probability of intermediate reactants interacting with the surface,thereby promoting efficient C–C coupling and enhancing the yield of C_(2.)*** findings provide valuable insights into targeted design strategies for Cu catalysts used in the eCO_(2.RR.

关键词： Strain effect CO_(2.electroreduction to C^(2.) Catalytic selectivity Copper catalyst Water coverage

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聚丙烯腈复合纳米纤维膜的制备及其对金属离子的吸附性能

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华东理工大学学报（自然科学版） 2024年第1期50卷 36-45页

作者：赵振杰杨雪红马坤朱志华奚桢浩王杰华东理工大学化工学院化学工程联合国家重点实验室上海200237 中国石化上海石油化工股份有限公司上海200540

以羧基化聚丙烯腈(CPAN)为原料,通过复合改性和接枝改性的方式,制备β-环糊精(β-CD)/CPAN-g-聚乙烯亚胺(PEI)复合纳米纤维膜,为体系引入亲水的β-CD和吸附性能优异的PEI。通过红外光谱仪、X射线衍射仪、万能材料试验机、场发射扫描电... 详细信息

以羧基化聚丙烯腈(CPAN)为原料,通过复合改性和接枝改性的方式,制备β-环糊精(β-CD)/CPAN-g-聚乙烯亚胺(PEI)复合纳米纤维膜,为体系引入亲水的β-CD和吸附性能优异的PEI。通过红外光谱仪、X射线衍射仪、万能材料试验机、场发射扫描电镜等仪器对复合纳米纤维膜进行结构及性能表征,使用等离子体发射光谱仪、X射线光电子能谱仪探究复合纳米纤维膜对Cd^(2.)和Pb^(2.)的吸附性能及吸附机理。结果表明:改性得到的β-CD/CPAN-g-PEI复合纳米纤维膜具有优异的吸附性能,同时保留了纤维膜原有的力学性能,其对Cd^(2.)和Pb^(2.)的最大吸附量分别为176.67 mg/g和2.0.83 mg/g,吸附过程符合拟二级动力学模型和Langmuir等温吸附模型,且循环使用5次后仍保持80%以上的吸附性能。

关键词：聚丙烯腈环糊精静电纺丝吸附金属离子

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Construction of surface lattice oxygen in metallic N-CuCoS1.97 porous nanowire for wearable Zn-air battery

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Journal of Energy Chemistry 2019年第7期28卷 1-9页

作者： Jie Yin Binbin Wei Yuxuan Li Yefei Li Pinxian xi state key {2. of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Provinceand College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000GansuChina Petrochina Lanzhou Lubricating Oil R&D Institute Lanzhou 730000GansuChina Collaborative Innovation Center of Chemistry for Energy material Key Laboratory of Computational Physical Science(Ministry of Education)Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsDepartment of ChemistryFudan UniversityShanghai 200433China

Achieving high activity and stability oxygen evolution reaction(OER) catalysts to optimize the efficiency of metal-air battery, water splitting and other energy conversion devices, remains a formidable ***, we demonstrate the metallic porous nanowires arrays with abundant defects via nitrogen and copper codoped CoS1.97 nanowires(N-CuCoS1.97 NWs). The N-CuCoS1.97 NWs can serve as an excellent OER self-supported electrode with an overpotential of 2.0 mV(j = 10 m A cm-2. and remarkable long-term stability. The X-ray absorption near-edge structure(XANES) and X-ray photoelectron spectrum(XPS) measurements confirmed the surface lattice oxygen created on the N-CuCoS1.97 NWs during OER. Then, the density function theory(DFT) results evident that lattice oxygen constructed surface of N-CuCoS1.97 NWs has more favorable OER energetic profiles and absorption for reaction intermediate. More importantly,the flexible and wearable Zn-air battery fabricated by the N-CuCoS1.97 NWs shows excellent rechargeable and mechanical stability, which can be used in portable mobile device.

关键词： DFT calculation Porous nanowires Electrocatalyst OER Zn-air battery

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Plasmonic Cu_(2.)S_(2.)nanocages for novel solar photothermal nanoink and nanofilm

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Nano Research 2022年第4期15卷 3161-3169页

作者： Min xi Longchang Xu Nian Li Shudong Zhang Zhenyang Wang Institute of Solid state Physics and key {2. of Photovoltaic and Energy Conservation materials Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China The key laboratory Functional Molecular Solids Ministry of Education Anhui Normal UniversityWuhu 241002China school of Mechatronics and Vehicle engineering Chongqing Jiaotong UniversityChongqing 400074China

Copper sulfide(Cu_(x)S)as a plasmonic solar photothermal semiconductor material that expands the light collection range by altering localized surface plasmon resonance(LSPR)to the near-to mid-infrared(IR)spectral *** versatile synthesis strategies of Cu_(x)S nanostructure offer its variability of morphology and provide additional freedom in tuning the optical ***,nanocage(or nanoshell)has hybridized plasmon resonances as a result of super-positioned nanosphere and nanocavity,which extends its receiving range of solar spectrum and increases light-to-heat conversion ***,we offer novel“nanoink”and“nanofilm”developed from colloidal Cu_(2.)S_(2.)nanocages with excellent solar photothermal *** combining experimental measurement and theoretical calculation,we estimated the optical properties of covellite Cu_(2.)S_(2.).And based on obtained dielectric functions,we then calculated its solar photothermal performance,which was further validated by our experimental *** simulation results showed that hollow Cu_(2.)S_(2.)nanocages have excellent solar photothermal performance,and exhibit much higher solar photothermal conversion efficiency than solid Cu_(2.)S_(2.)nanospheres.

关键词： plasmonics solar photothermal hybridized plasmon Cu_(2.)S_(2.)nanocages

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mechanical properties and friction behaviors of CNT/AlSi_(10)Mg composites produced by spark plasma sintering

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International Journal of Minerals,Metallurgy and materials 2017年第5期24卷 584-593页

作者： Lin-zhi Wang Ying Liu Jiao-jiao Wu xi Zhang Chongqing key laboratory of Additive Manufacturing Technology and Systems Chongqing Institute of Green and Intelligent TechnologyChinese Academy of Sciences College of material science and {2. Sichuan University College of material science and {2. Southwest Jiaotong university

The mechanical properties and friction behaviors of CNT/AlSi10Mg composites produced by spark plasma sintering (SPS) were investigated. The results showed that the densities of the sintered composites gradually increased with increasing sintering temperature and that the highest microhardness and compressive strength were achieved in the specimen sintered at 450A degrees C. CNTs dispersed uniformly in the Al-Si10Mg matrix when the addition of CNTs was less than 1.5wt%. However, when the addition of CNTs exceeded 1.5wt%, the aggregation of CNTs was clearly observed. Moreover, the mechanical properties (including the densities, compressive strength, and microhardness) of the composites changed with CNT content and reached a maximum value when the CNT content was 1.5wt%. Meanwhile, the minimum average friction coefficient and wear rate of the CNT/AlSi10Mg composites were obtained with 1.0wt% CNTs.

关键词： metal matrix composites carbon nanotubes (CNTs) aluminum silicon magnesium alloys spark plasma sintering mechanical properties friction

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Investigation on the Anisotropic Transformation Surfaces of Super-Elastic NiTi Shape Memory Alloys Under Multiaxial Cyclic Loading Conditions

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Acta Mechanica Solida Sinica 2018年第6期31卷 744-757页

作者： Bo Qiu Qianhua Kan Tianxing Zhao xi xie Guozheng Kang state key {2. of Traction Power Southwest Jiaotong UniversityChengdu 610031China Applied Mechanics and Structure Safety key laboratory of Sichuan Province School of Mechanics and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

The cyclic transformation behaviors of polycrystalline super-elastic NiTi shape memory alloys (SMAs)under multiaxial loading paths with different angles between axial and torsional loading orientations were experimentally *** experimental results showed that the start stresses of forward and reverse transformations decreased with the increase'in the number of cycles and exhibit obvious anisotropic *** start stresses of forward and reverse transformations in the tensile and torsional directions did not satisfy the yon Mises *** shape of transformation surface during the forward and reverse transformations evolved with the increase in the number of ***,new cyclic anisotropic transformation surfaces were established by introducing an anisotropic tensor into the von Mises equivalent stress based on a typical transformation criterion related to J2.and ***,the evolution equations of material parameters used in the proposed transformation surfaces were established to describe the subsequent evolutions of transformation ***,the start stresses of forward and reverse transformations predicted using the proposed transformation surfaces were compared with the experimental *** shows that the proposed transformation surfaces can reasonably describe the start stresses of forward and reverse transformations,which are helpful for establishing a three-dimensional cyclic constitutive model to describe the cyclic transformation behaviors of super-elastic NiTi SMAs.

关键词： Shape memory alloy Anisotropic response Transformation surface Stress invari- ant Multiaxial cyclic loading

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Deformation and failure behavior of heterogeneous Mg/SiC nanocomposite under compression

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Journal of Magnesium and Alloys 2022年第12期10卷 3433-3446页

作者： xi Luo Jinling Liu Leigang Zhang Xu He Ke Zhao Linan An state key {2. of Traction Power&school of Mechanics and engineering Southwest Jiaotong UniversityChengduSichuan610031China Applied Mechanics and Structure Safety key laboratory of Sichuan Province Southwest Jiaotong UniversityChengduSichuan610031China Department of materials science and {2. University of Central FloridaOrlandoFL32816United States

The heterogeneous magnesium(Mg) matrix nanocomposite with dispersed soft phase exhibits high strength and toughness. Herein, the deformation behavior and failure process were investigated to reveal the unique mechanical behavior of the heterogeneous microstructure under compression. The extensive plastic deformation is accompanied by the flattening and tilting of the soft phase, inhibiting strain localization and leading to strain hardening. Moreover, a stable crack multiplication process is activated, which endows high damage tolerance to the heterogeneous Mg matrix nanocomposites. The final failure of the composite is caused by crack coalescence in the shear plane along a tortuous path. The presence of dispersed soft phases within the hard matrix induces a noticeable change in mechanical response. Especially,the malleability of the heterogeneous Mg matrix nanocomposite is two and ten times higher than that of pure Mg and the homogeneous Mg matrix nanocomposite, respectively. The current study provides a novel strategy to break the trade-off between strength and toughness in metal matrix nanocomposites.

关键词： Magnesium matrix nanocomposites Heterogeneous structure Malleability Microstructural evolution

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增材铜合金拉伸力学行为的卷积神经网络预测

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计算力学学报 2024年第5期41卷 843-850页

作者：肖庆晖张仁嘉刘士杰胡文轩吕晨晞朱思瑛易敏南京航空航天大学航空航天结构力学及控制全国重点实验室南京210016 北京宇航系统工程研究所北京100076 北京航天动力研究所低温液体推进技术实验室北京100076

深度学习因其在处理复杂数据和解决复杂问题方面的显著优势而备受关注,已应用于材料性能预测领域。本文提出了一种结合卷积神经网络模型与晶体塑性有限元方法的预测框架,在晶体塑性模型中考虑了增材铜合金(CuCrZr)固溶强化、位错强化以... 详细信息

深度学习因其在处理复杂数据和解决复杂问题方面的显著优势而备受关注,已应用于材料性能预测领域。本文提出了一种结合卷积神经网络模型与晶体塑性有限元方法的预测框架,在晶体塑性模型中考虑了增材铜合金(CuCrZr)固溶强化、位错强化以及晶界强化的贡献,实现了基于增材铜合金的晶体学织构极图、微结构图和晶粒尺寸预测单轴拉伸力学行为的目标。首先,基于实验结果对晶体塑性模型参数进行校正,验证了模型的准确性及预测能力。随后,使用参数校正后的晶体塑性模型对增材铜合金不同的代表体积元进行了一系列的有限元模拟,并利用这些模拟结果对卷积神经网络模型进行了训练、验证与测试。研究结果表明,该卷积神经网络模型在保证预测精度的同时,显著减少了计算时间,展示了其在增材铜合金力学性能预测方面的应用前景。

关键词：增材制造卷积神经网络晶体塑性铜合金

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Effect of milling duration on hydrogen storage thermodynamics and kinetics of ball-milled Ce-Mg-Ni-based alloy powders

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Journal of Iron and Steel Research International 2018年第7期25卷 746-754页

作者： Dian-chen Feng Hao Sun xi-tao Wang Yang-huan Zhang school of materials and Metallurgy Inner Mongolia University of Science and Technology Baotou 014010 Inner Mongolia China state key {2. for Advanced Metals and materials University of Science and Technology Beijing Beijing 100083 China Department of Functional material Research Central Iron and Steel Research Institute Beijing 100081 China

To improve the hydrogen storage performance of CeMg12.type alloys, partially substituting Mg with Ni in the alloy was conducted. The way to synthesize the target alloy powders was the mechanical milling method, by which the CeMg11-Ni ＋ x wt% Ni （x = 100, 2.0） alloy powders with nanocrystalline and amorphous structure were obtained. The influence of the milling time and Ni content on the hydrogen storage properties of the alloys was discussed. The X-ray diffractometer and high-resolution transmission electron microscope were used to investigate the microstructures of the ball-milled alloys. The hydrogenation/dehydrogenation dynamics were studied using a Sievert instrument and a differential scanning calorimeter which was linked with a H2.detector. The hydrogen desorption activation energies of the alloy hydrides were evaluated by Arrhenius and Kissinger equations. From the results point of views, there is a little decline in the thermo- dynamic parameters （enthalpy and entropy changes） with the increase in Ni content. However, the alloys desorption and absorption dynamics are improved distinctly. What is more, the variation of milling time results in a dramatic influence on the hydrogen storage performances of alloys. Various maximum values of the hydrogen capacities correspond to different milling time, which are 5.805 and 6.016 wt% for the CeMgllNi ＋ x wt% Ni （x = 100, 2.0） alloys, respectively. The kinetics tests suggest that the hydrogen absorption rates increase firstly and then decrease with prolonging the milling time. The improvement of the gaseous hydrogen storage kinetics results from the decrease in the activation energy caused by the increase in Ni content and milling time.

关键词： CeMg12.alloy mechanical milling Amorphous - Activation energy Hydrogen storage kinetics Thermodynamics

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