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Journal of Magnesium and Alloys 2024年第3期12卷 1186-1203页

作者： Biaobiao Yang Javier LLorca IMdeA Materials Institute C/Eric Kandel 2GetafeMadrid 28906Spain department of Materials science Polytechnic University of Madrid/Universidad Politécnica de MadridE.T.S.de Ingenieros de CaminosMadrid 28040Spain

A large number of anomalous extension twins,with low or even negative twinning schmid factors,were found to nucleate and grow in a strongly textured Mg-1Al alloy during tensile deformation along the extruded *** deformation mechanisms responsible for this behaviour were investigated through in-situ electron back-scattered diffraction,grain reference orientation deviation,and slip trace-modified lattice *** was found that anomalous extension twins nucleated mainly at the onset of plastic deformation at or near grain boundary triple *** were associated with the severe strain incompatibility between neighbour grains as a result from the differentbasal slip-induced lattice ***,the anomalous twins were able to grow with the applied strain due to the continuous activation ofbasal slip in different neighbour grains,which enhanced the strain *** results reveal the complexity of the deformation mechanisms in Mg alloys at the local level when deformed along hard orientations.

关键词： Magnesium extension twinning In-situ electron back-scattered diffraction basal slip deformation mechanisms.

Recent Progress on Metal–Organic Framework and Its derivatives as Novel Fire Retardants to Polymeric Materials

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Nano-Micro Letters 2020年第12期12卷 173-193页

作者： Jing Zhang Zhi Li Xiao‑Lin Qi de‑Yi Wang IMdeA Materials Institute C/Eric Kandel 228906 GetafeMadridSpain Universidad Politécnica de Madrid E.T.S.de Ingenieros de Caminos28040 MadridSpain China‑spain Collaborative Research Center for Advanced Materials School of Materials Science and EngineeringChongqing Jiaotong UniversityChongqing 400074People’s Republic of China

High flammability of polymers has become a major issue which has restricted its ***,highly crystalline materials and metal–organic frameworks(MOFs),which consisted of metal ions and organic linkers,have been intensively employed as novel fire retardants(FRs)for a variety of polymers(MOF/polymer).the MOFs possessed abundant transition metal species,fire-retardant elements and potential carbon source accompanied with the facile tuning of the structure and property,making MOF,its derivatives and MOF hybrids promising for fire retardancy *** recent progress and strategies to prepare MOF-based FRs are emphasized and *** fire retardancy mechanisms of MOF/polymer composites are explained,which may guide the future design for efficient MOF-based ***,the challenges and prospects related to different MOFbased FRs are also discussed and aim to provide a fast and holistic overview,which is beneficial for researchers to quickly get up to speed with the latest development in this field.

关键词： Metal–organic frameworks Hybrids Polymers Composites Fire retardancy

FRACtIONAL-steP FINIte eLeMeNt MetHOD FOR CALCULAtION OF 3-D FRee sURFACe PROBLeM UsING LeVeL set MetHOD

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Journal of Hydrodynamics 2006年第6期18卷 742-747页

作者： ZHAO Lan-hao LI tong-chun WANG Ling HeRReROs M. I. PAstOR M. College of Water Conservancy and Hydropower engineering Hohai University Naniing 210098 China Anhui survey and design Institute of Water Conservancy and Hydropower Hefei 230022 China cedex and e.t.s. de caminos Madrid Spain

A two-step taylor-Galerkin fractional-step finite element method, which is of second order accuracy in space and time, was proposed for the three-dimensional free surface problem. With this method, the intermediate velocity was explicitly obtained by neglecting pressure gradient term, and then the velocity was corrected by adding the effects of pressure once the pressure field had been obtained from the pressure Poisson equation. the level set approach was applied to track implicitly the free surface. In order to track the free surface, the transport equation of the level set function was solved at each time step and the level set function is reinitialized through iteration to maintain it as a distance function. the governing equations of the system were discretized by the two- step taylor-Galerkin method, which is of high-order accuracy and easy to be used. the validity and reliability of this method in this article were proved by two numerical examples.

关键词： level set free surface two steps taylor-Galerkin fractional step FeM

Recent Advances on early-stage Fire-Warning systems: Mechanism, Performance, and Perspective

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Nano-Micro Letters 2022年第12期14卷 106-136页

作者： Xiaolu Li Antonio Vazquez-Lopez Jose sanchez del Rio saez de-Yi Wang IMdeA Materials Institute C/Eric Kandel228906 GetafeMadridSpain e.t.s.de Ingenieros de caminos Universidad Politecnica de MadridCalle Profesor Aranguren 328040 MadridSpain departamento de Ingenieria electrica Electronica Automatica y Fisica AplicadaETSIDIUniversidad Politecnica de MadridRonda de Valencia 328012 MadridSpain

early-stage fire-warning systems(eFWss)have attracted significant attention owing to their superiority in detecting fire situations occurring in the pre-combustion *** progress on eFWss has been achieved recently,and they have presented a considerable possibility for more evacuation time to control constant unintentional fire hazards in our daily *** review mainly makes a comprehensive summary of the current eFWss,including the working mechanisms and their *** to the different working mechanisms,fire alarms can be classified into graphene oxide-based fire alarms,semiconductor-based fire alarms,thermoelectric-based fire alarms,and fire alarms on other working ***,the challenge and prospect for eFWss are briefly provided by comparing the art of state of fire *** work can propose a more comprehensive understanding of eFWss and a guideline for the cutting-edge development direction of eFWss for readers.

关键词： smart thermosensitive fire sensors Working mechanism Response time signal conversion

the relation between ductility at high temperature and solid solution in Mg alloys

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Journal of Magnesium and Alloys 2022年第1期10卷 241-256页

作者： D.F.shi C.M.Cepeda-Jiménez M.t.Pérez-Prado IM deA Materials Institute C/Eric Ka ridel228906 GetafeMadridSpain department of Materials science Polytechnic University of Madrid/Universidad Politecnica de MadridE.T.S.de Ingenieros de Caminos28040MadridSpain department of Physical Metallurgy CENIMCSICAv.Gregorio del Amo 828040 MadridSpain

this work investigates the effect of solid solution on ductility and on the activation of individual deformation mechanisms at moderate temperatures and at quasi-static strain rates in Mg-Zn and Mg-Al alloys. With that aim, four solid solution Mg-Zn and Mg-Al binary alloy ingots containing 1 and 2 wt.% solute atoms were subjected to hot rolling and subsequent annealing to generate polycrystals with similar average grain size and basal-type texture for each composition. the activity of the different slip systems after tensile testing at 150°C and at 250°C was evaluated in pure Mg and in the alloys by eBsD-assisted slip trace analysis. In addition, segregation of Zn and Al atoms at grain boundaries during the thermo-mechanical processing was characterized by HAADF-steM and eDX. It was found that while the addition of Al and Zn atoms to pure Mg does not lead to major changes in the mechanical strength at the investigated temperatures, it does enhance ductility significantly, especially at 250℃. Our results show that this increase in ductility cannot be attributed to a higher activation of non-basal systems in the alloys, as reported earlier, as the incidence of non-basal systems is indeed considerably higher in pure Mg. this work suggests, on the contrary, that the ductility increase may be attributed to the presence of a more homogenous basal activity in the alloys due to a lower degree of orientation clustering, to grain boundary solute segregation, and to a higher slip diffusivity at grain interiors.

关键词： Magnesium solute segregation slip trace analysis Ductility deformation mechanisms

High-energy sodium-ion hybrid capacitors through nanograin-boundary-induced pseudocapacitance of Co_(3)O_(4) nanorods

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Journal of energy Chemistry 2022年第6期31卷 338-346,I0009页

作者： Wenliang Feng Venkata sai Avvaru steven JHinder Vinodkumar etacheri IMdeA Materials Institute C/Eric Kandel 2GetafeMadrid 28906Spain Universidad Politécnica de Madrid E.T.S.de Ingenieros de Caminos28040 MadridSpain Universidad Autónoma de Madrid C/Francisco Tomás y Valiente728049 MadridSpain surface Analysis Laboratory Faculty of Engineering and Physical Sciences University of Surrey GuildfordSurrey GU27XHUnited Kingdom

sodium-ion hybrid capacitors (sICs) have been proposed to bridge performance gaps between batteries and supercapacitors,and thus realize both high energy density and power density in a single ***,applications of sICs are severely restricted by their insufficient energy densities (esulted from the kinetics imbalance between cathodes and ***,we report a nanograin-boundary-rich hierarchical Co_(3)O_(4) nanorod anode composed of~20 nm *** pseudocapacitance (up to 72%@1.0 mV/s) is achieved through nanograin-boundary-induced pseudocapacitive-type Na^(+) storage ***_(3)O_(4) nanorod anode delivers in this case highly reversible capacity (810 mAh/g@0.025 A/g),excellent rate capability (335 mAh/g@5.0 A/g),and improved cycle stability (100 cycles@1.0 A/g with negligible capacity degradation).the outstanding performance can be credited to the hierarchical morphology of Co_(3)O_(4) nanorods and the well-designed nanograinboundaries between nanocrystallites that avoid particle agglomeration,induce pseudocapacitive-type Na^(+) storage,and accommodate volume variation during sodiation-desodiation *** of the Co_(3)O_(4) nanorods not only generates defects for extra surficial Na^(+) storage but also increases the electronic conductivity for efficient charge separation and lowers energy barrier for Na^(+) *** of conventional reaction mechanism and pseudocapacitive-type Na^(+) storage enables high specific capacity,rapid Na^(+) diffusion,and improved structural stability of the Co_(3)O_(4) nanorod *** sIC integrating this highly pseudocapacitive anode and activated carbon cathode delivers exceptional energy density (175 Wh/kg@40 W/kg),power density (6632 W/kg@37 Wh/kg),cycle life (6000 cycles@1.0 A/g with a capacity retention of 81%),and coulombic efficiency (~100%).

关键词： sodium-ion hybrid capacitor Cobalt oxide nanorod Nanograin-boundary Pseudocapacitance

experimental study on lightweight expanded clay at particle level:Breakage of isolated grains

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Journal of Rock Mechanics and Geotechnical engineering 2023年第7期15卷 1846-1858页

作者： elías Roces-Alonso Jose estaire Miriam Martín-Ruiz Jesús González-Galindo ets de Ingenieros de caminos Universidad Politécnica de MadridSpain Laboratorio de Geotecnia CEDEXMadridSpain

In this study,more than 1500 particles of lightweight expanded clay aggregate(LeCA)are individually loaded up to breakage,following different patterns of contact(from 2 to 7)using a purpose-built ***,a statistical model for predicting the number of fragments into which a grain breaks as a function of the number of contacts and their diameter is *** number of fragments is found to follow a statistical binomial-type distribution function that depends on the number of *** addition,a model based on Bayesian networks,capable of assessing the number of fragments and their size(measured as normalized weight)as a function of the number of contacts,is *** proposed method is applicable when performing discrete element method(deM)simulations on granular media in which grain breakage plays a relevant role.

关键词： Lightweight expanded clay aggregate(LeCA) Grain fragmentation Grain breakage Biaxial grain load

effect of ti additions on microstructure and mechanical properties of Cu-Cr-Zr alloy

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Journal of Materials science & technology 2023年第32期163卷 69-80页

作者： Chenying shi Muzhi Ma Biaobiao Yang Yuling Liu Yushen Huang Yong Du state Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China school of Materials science and engineering Central South UniversityChangsha 410083China IMdeA Materials Institute C/Eric Kandel 2Getafe28906 MadridSpain department of Materials science Polytechnic University of Madrid/Universidad Politécnica de MadridE.T.S.de Ingenieros de Caminos28040 MadridSpain

ti additions in Cu–Cr–Zr alloys are useful for achieving high mechanical *** this work,the influence of ti contents(0.25 wt%,0.6 wt%,and 1.02 wt%)on the microstructure,mechanical,and electrical properties of Cu–Cr–Zr alloys has been investigated experimentally,along with thermodynamic and kinetic *** electrical conductivity decreased but the hardness/strength increased with increasing ti *** lower electrical conductivity is due to increased electron scattering through the solution of more ti atoms in the Cu *** for the higher hardness/strength,it is mainly owing to higher dislocation density and finer FCC-Cr ***,a model considering the size distributions of precipitates is adopted to calculate precipitation strengthening *** calculated yield strengths are consistent with the experimental ones for the *** thermodynamic and kinetic calculations reveal that increasing ti content can facilitate the nucleation of FCC-Cr but enhance its activation energy,hence hindering the growth *** present work study can provide an effective strategy for producing copper alloys with expected performance.

关键词： Cu-Cr-Zr-ti alloy Mechanical and electrical properties Microstructure Precipitation behavior thermodynamic and kinetic calculations

A new physical simulation tool to predict the interface of dissimilar aluminum to steel welds performed by friction melt bonding

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Journal of Materials science & technology 2019年第9期35卷 2048-2057页

作者： t.sapanathan N. Jimenez-Mena I. sabirov M.A. Monclus J.M. Molina-Aldaregui P. Xia L. Zhao A. simar Institute of Mechanics Materials and Civil EngineeringUCLouvain1348 Louvain-la-NeuveBelgium IMdeA Materials Institute Calle Eric Kandel 228906 GetafeMadridSpain Universidad Politicnica de Madrid E.T.S. de Ingenieros de Caminos28040 MadridSpain

Optimization of the intermetallic layer thickness and the suppression of interfacial defects are key elements to improve the load bearing capacity of dissimilar joints. However, till date we do not have a systematic tool to investigate the dissimilar joints and the intermetallic properties produced by a welding condition. Friction Melt Bonding (FMB) is a recently developed technique for joining dissimilar metals that also does not exempt to these challenges. the FMB of DP980 and A16061-t6 was investigated using a new physical simulation tool, based on Gleeble thermo-mechanical simulator, to understand the effect of individual parameter on the intermetallic formation. the proposed method demonstrates its capability in reproducing the intermetallic characteristics, including the thickness of intermetallic bonding layer, the morphology and texture of its constituents (Fe2AU and Fe4Ali3), as well as their nanohardness and reduced modulus. the advantages of physical simulation tool can enable novel developing routes for the development of dissimilar metal joining processes and facilitate to reach the requiring load bearing capacity of the joints.

关键词： Physical simulation Interface Intermetallics Nanoindentation Joining

Levelset方法求解三维大幅晃动问题的分步有限元法

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水动力学研究与进展（A辑） 2006年第4期21卷 433-438页

作者：赵兰浩李同春牛志伟 M.Pastor 河海大学水利水电工程学院江苏南京210098 cedex and e.t.s.de caminos MadridSpain

取与容器固结的坐标系,将外激励视为质量力,针对刚性容器内流体三维非线性大幅晃动问题,提出了在时间和空间上均具有二阶精度的两步taylor-Galerk in分步有限元方法。该法首先显式地求解忽略压力梯度项的中间速度场,然后由压力泊松方程... 详细信息

取与容器固结的坐标系,将外激励视为质量力,针对刚性容器内流体三维非线性大幅晃动问题,提出了在时间和空间上均具有二阶精度的两步taylor-Galerk in分步有限元方法。该法首先显式地求解忽略压力梯度项的中间速度场,然后由压力泊松方程求得压力场,再根据求得的压力对速度场进行修正。求解中利用Level-set方法隐式地追踪自由面,即在每个时间步求解Level-set函数随水流的输运方程,并通过迭代的方法对其进行重新初始化,以保持为距离的函数,从而达到捕捉自由面的目的。控制方程统一采用简单方便且具有较高精度的两步taylor-Galerk in格式进行离散,并通过两个算例验证了本文数值方法的正确性和有效性。

关键词：大幅晃动 Level set 两步taylor—Galerkin 分步有限元