Magnesium(Mg)alloys are promising candidates for biodegradable implants and medical devices due to their biocompatibility,mechanical properties,and ability to degrade in vivo,thereby eliminating the need for secondary...Magnesium(Mg)alloys are promising candidates for biodegradable implants and medical devices due to their biocompatibility,mechanical properties,and ability to degrade in vivo,thereby eliminating the need for secondary removal surgeries[1,2].However,their clinical adoption is hindered by rapid corrosion in physiological environments[3–5].Due to the high chemical reactivity of magnesium substrates and the inability of primary corrosion degradation products to form ideal protective layers,no effective scientific guidance has yet been identified from fundamental material science to address the rapid degradation of bare Mg[6–8].Surface modification strategies equivalently create new materials wrapped in a matrix,which can thus be extensively explored to enhance the corrosion resistance of Mg alloys while endowing them with tailored biological functionalities[9,10].展开更多
Magnesium-based hydrogen storage materials are gaining significant attention due to their high hydrogen storage capacity and abundant availability.However,they encounter challenges,including slow hydrogen absorption a...Magnesium-based hydrogen storage materials are gaining significant attention due to their high hydrogen storage capacity and abundant availability.However,they encounter challenges,including slow hydrogen absorption and desorption kinetics and elevated operating temperatures.To address these issues,researchers have employed two main strategies:nanostructuring and the introduction of catalysts.This review provides a comprehensive overview of recent advancements in the modification of MgH_(2),emphasizing the impact of nanostructuring on enhancing hydrogen storage performance.It also examines the role of various catalysts,including carbon-based materials,transition metals and alloys,their oxides and halides,and composites,in improving hydrogen absorption and desorption characteristics.Studies indicate that these modifications can substantially lower the hydrogen absorption and desorption temperatures while enhancing kinetic performance.Furthermore,the effectiveness of catalysts is influenced by their type,dispersion,and interaction with magnesium-based materials and the catalytic mechanism,thereby elucidating the underlying catalytic mechanisms.The review concludes by discussing the current challenges and future directions in this field,aiming to provide theoretical insights for the practical application of magnesium-based hydrogen storage materials.展开更多
P-type Mg_(3)Sb_(2)-based Zintls have attracted considerable interest in the thermoelectric(TE)field due to their environmental friendliness and low cost.However,compared to their n-type counterparts,they show relativ...P-type Mg_(3)Sb_(2)-based Zintls have attracted considerable interest in the thermoelectric(TE)field due to their environmental friendliness and low cost.However,compared to their n-type counterparts,they show relatively low TE performance,limiting their application in TE devices.In this work,we simultaneously introduce Bi alloying at Sb sites and Ag doping at Mg sites into the Mg_(3)Sb_(2)to coopera-tively optimize the electrical and thermal properties for the first time,acquiring the highest ZT value of∼0.85 at 723 K and a high average ZT of 0.39 in the temperature range of 323-723 K in sample Mg_(2.94)Ag_(0.06)Sb_(1.9)Bi_(0.1).The first-principle calculations show that the codoping of Ag and Bi can shift the Fermi level into the valence band and narrow the band gap,resulting in the increased carrier concentration from 3.50×10^(17)cm^(-3)in the reference Mg 3 Sb 0.9 Bi 0.1 to∼7.88×10^(19)cm^(-3)in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.As a result,a remarkable power factor of∼778.9μW m^(-1)K^(-2)at 723 K is achieved in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.Meanwhile,a low lattice thermal conductivity of∼0.48 W m^(-1)K^(-1)at 723 K is also obtained with the help of phonon scattering at the distorted lattice,point defects,and nano-precipitates in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.The synergistic effect of using the multi-element co-doping/-alloying to optimize electrical properties in Mg_(3)Sb_(2)holds promise for further improving the TE performance of Zintl phase materials or even others.展开更多
An unprecedentedly short milling time of 30 s was applied to gas-atomized MnAl powder in order to develop permanent magnet properties and,in particular,coercivity.It is shown that such a short processing time followed...An unprecedentedly short milling time of 30 s was applied to gas-atomized MnAl powder in order to develop permanent magnet properties and,in particular,coercivity.It is shown that such a short processing time followed by annealing results in efficient nanostructuring and controlled phase transformation.The defects resulting from the microstrain induced during milling,together with the creation of the bphase during post-annealing,act as pinning centers resulting in an enhanced coercivity.This study shows the importance of finding a balance between the formation of the ferromagnetic s-MnAl phase and the bphase in order to establish a compromise between magnetization and coercivity.A coercivity as high as 4.2 kOe(1 Oe=79.6 A·m^-1)was obtained after milling(30 s)and annealing,which is comparable to values previously reported in the literature for milling times exceeding 20 h.This reduction of the postannealing temperature by 75℃ for the as-milled powder and a 2.5-fold increase in coercivity,while maintaining practically unchanged the remanence of the annealed gas-atomized material,opens a new path for the synthesis of isotropic MnAl-based powder.展开更多
In this review we consider the development of optical near-field imaging and nanostructuring by means of laser ablation since its early stages around the turn of the century.The interaction of short,intense laser puls...In this review we consider the development of optical near-field imaging and nanostructuring by means of laser ablation since its early stages around the turn of the century.The interaction of short,intense laser pulses with nanoparticles on a surface leads to laterally tightly confined,strongly enhanced electromagnetic fields below and around the nano-objects,which can easily give rise to nanoablation.This effect can be exploited for structuring substrate surfaces on a length scale well below the diffraction limit,one to two orders smaller than the incident laser wavelength.We report on structure formation by the optical near field of both dielectric and metallic nano-objects,the latter allowing even stronger and more localized enhancement of the electromagnetic field due to the excitation of plasmon modes.Structuring with this method enables one to nanopattern large areas in a one-step parallel process with just one laser pulse irradiation,and in the course of time various improvements have been added to this technique,so that also more complex and even arbitrary structures can be produced by means of nanoablation.The near-field patterns generated on the surface can be read out with high resolution techniques like scanning electron microscopy and atomic force microscopy and provide thus a valuable tool-in conjunction with numerical calculations like finite difference time domain(FDTD)simulations-for a deeper understanding of the optical and plasmonic properties of nanostructures and their applications.展开更多
23K2O·27Nb2O5·50SiO 2（KNS）,13K2O·10Na2O·27Nb2O5·50SiO 2（KNaNS） and 15K2O·12Li2O·27Nb2O5·46SiO2（KLiNS） transparent glasses were synthesized by melt-quenching technique,and ...23K2O·27Nb2O5·50SiO 2（KNS）,13K2O·10Na2O·27Nb2O5·50SiO 2（KNaNS） and 15K2O·12Li2O·27Nb2O5·46SiO2（KLiNS） transparent glasses were synthesized by melt-quenching technique,and studied by differential thermal analysis（DTA）,X-ray diffraction（XRD） and high-resolution transmission electron microscopy（HRTEM） to reveal the effect of the devitrification behaviour on transparent nanostructure.Just above the glass transition temperature T g in the KNS glass,an unidentified phase was formed,while in KNaNS and KLiNS,mixed-alkali niobate phases with tungsten bronze structure were obtained by bulk crystallization.Heat treatments at T g performed on the KNS glass resulted in the transparent nanostructure with second order harmonic generation（SHG） activity.Heat treatment for 10 h on KNaNS and KLiNS decreased the first DTA exothermic peaks（at least 24C）,indicating the bulk nucleation,which was confirmed by the DTA in comparison with the powdered as-quenched samples.KNaNS and KLiNS showed similar XRD profiles as the K3Li2Nb5O15 crystal with the five most intense peaks at 22.7,29.4,32.3,46.3 and 52.0 deg.HRTEM micrograph showed clear-cut nano-sized circular domains and spherical nanocrystals dispersed into the amorphous matrix.展开更多
Preparation and thermoelectric properties of nanostructured n-type Mg2Si bulk materials were reported. Nanosized Mg2Si powder was obtained by mechanical milling of the microsized Mg2Si powder prepared by solid-state r...Preparation and thermoelectric properties of nanostructured n-type Mg2Si bulk materials were reported. Nanosized Mg2Si powder was obtained by mechanical milling of the microsized Mg2Si powder prepared by solid-state reaction. The bulk materials with 30 nm and 5 μm were prepared by spark plasma sintering of the nanosized and microsized Mg2Si powder, respectively. Both the samples show n-type conduction and the Seebeck coefficient of the sintered samples increase determinately with the grain size decrease from 5 μm to 30 nm. On the other hand, the electrical and thermal conductivity decrease with the decrease of grain size. Accordingly, decreasing their grain size increases their thermoelectric-figure-of-merit. A maximum thermoelectric figure of merit of 0.36 has been obtained for the nanostuctured Mg2Si sample at 823 K, which is 38% higher than that of microsized Mg2Si bulk materials and higher than results of other literatures. It could be expected that the properties of the nanocomposites could be further improved by doping optimization.展开更多
Self-organization processes in semiconductor materials on the example of nanostructuring of por-Si at long anodic etching of p-type Si in the electrolyte with internal source of the current are shown. In conditions of...Self-organization processes in semiconductor materials on the example of nanostructuring of por-Si at long anodic etching of p-type Si in the electrolyte with internal source of the current are shown. In conditions of a “soft” etching of the Si point defects are formed and in the subsequently occurs their spatial-temporal ordering. This leads to the ordering pores and the nanostructuring of por-Si. Self-organization mechanism of Si nanocrystallites islets is described by the effects of the elastically-deformative, defectively-deformative and capillary-fluctuation forces.展开更多
With the depletion of fossil fuels and global warming,there is an urgent demand to seek green,low-cost,and high-efficiency energy resources.Hydrogen has been considered as a potential candidate to replace fossil fuels...With the depletion of fossil fuels and global warming,there is an urgent demand to seek green,low-cost,and high-efficiency energy resources.Hydrogen has been considered as a potential candidate to replace fossil fuels,due to its high gravimetric energy density(142 MJ kg^(-1)),high abundance(H_(2)O),and environmentalfriendliness.However,due to its low volume density,effective and safe hydrogen storage techniques are now becoming the bottleneck for the"hydrogen economy".Under such a circumstance,Mg-based hydrogen storage materials garnered tremendous interests due to their high hydrogen storage capacity(~7.6 wt%for MgH_(2)),low cost,and excellent reversibility.However,the high thermodynamic stability(ΔH=-74.7 kJ mol^(-1)H_(2))and sluggish kinetics result in a relatively high desorption temperature(>300℃),which severely restricts widespread applications of MgH_(2).Nano-structuring has been proven to be an effective strategy that can simultaneously enhance the ab/de-sorption thermodynamic and kinetic properties of MgH_(2),possibly meeting the demand for rapid hydrogen desorption,economic viability,and effective thermal management in practical applications.Herein,the fundamental theories,recent advances,and practical applications of the nanostructured Mg-based hydrogen storage materials are discussed.The synthetic strategies are classified into four categories:free-standing nano-sized Mg/MgH_(2)through electrochemical/vapor-transport/ultrasonic methods,nanostructured Mg-based composites via mechanical milling methods,construction of core-shell nano-structured Mg-based composites by chemical reduction approaches,and multi-dimensional nano-sized Mg-based heterostructure by nanoconfinement strategy.Through applying these strategies,near room temperature ab/de-sorption(<100℃)with considerable high capacity(>6 wt%)has been achieved in nano Mg/MgH_(2)systems.Some perspectives on the future research and development of nanostructured hydrogen storage materials are also provided.展开更多
The effect of rolling to a total effective strain of 2 at the liquid nitrogen temperature and subsequent natural and artificial aging on the structure and service properties of the pre-quenched hot-pressed 2024 alumin...The effect of rolling to a total effective strain of 2 at the liquid nitrogen temperature and subsequent natural and artificial aging on the structure and service properties of the pre-quenched hot-pressed 2024 aluminum alloy was investigated.Using optical and electron microscopy,and X-ray analysis,it was found that the cryorolling did not qualitatively change the type of the initial coarse-fibered microstructure,but produced a well-developed nanocell substructure inside fibers.Further aging led to decomposition of the preliminary supersaturated and work-hardened aluminum solid solution and precipitation of strengthening phases in the statically recovered and/or recrystallized matrix.As a result,the rolled and naturally aged alloy demonstrated the yield and ultimate tensile strengths(YS=590 MPa,UTS=640 MPа)much higher than those in the pressed andТ6-heat treated alloy at equal elongation to failure(El^6%).Artificial aging at a temperature less than conventional T6 route could provide the extra alloy strengthening and the unique balance of mechanical properties,involving enhanced strength(YS=610 MPa,UTS=665 MPа)and ductility(El^10%),and good static crack resistance(the specific works for crack formation and growth were 42 and 18 k J/m^2,respectively)and corrosion resistance(the intensity and depth of intercrystalline corrosion were 23%and 50μm,respectively).展开更多
Femtosecond laser induced periodic surface structures(LIPSSs)are excellent biomimetic iridescent antireflective interfaces.In this work,we demonstrate the feasibility to develop tunable iridescent antireflective surfa...Femtosecond laser induced periodic surface structures(LIPSSs)are excellent biomimetic iridescent antireflective interfaces.In this work,we demonstrate the feasibility to develop tunable iridescent antireflective surfaces via simultaneous synthesis of functional metal-oxide nanomaterials,in situ deposition and hierarchical LIPSSs nanostructuring by means of femtosecond laser ablation(fs-LA)of tungsten(W)and molybdenum(Mo)in air.Adjusting the scanning interval from 1μm to 20μm allows the modulation of particle deposition rates on LIPSSs.Diminishing the scan interval enables a higher particle deposition rate,which facilitates the development of better UV-to-MIR ultrabroadband antireflective surfaces with a less pronounced iridescence.Through comparing the reflectance of hierarchical LIPSSs with different densities of loosely/tightly deposited particles,it is found that the deposited WO_(x)and MoO_(x)particle aggregates have high UV-to-MIR ultrabroadband absorbance,especially extraordinary in the MIR range.Loosely deposited particles which self-assembly into macroporous structures outperform tightly deposited particles for ultrabroadband antireflective applications.The presence of loosely deposited MoO_(x)and WO_(x)particle absorbers can cause up to 80%and 60%enhancement of antireflectance performances as compared to the tightly particle deposited LIPSSs samples.One stone of"fs-LA technique"with three birds of(particle generation,in situ deposition and LIPSS hierarchical nanostructuring)presented in this work opens up new opportunities to tune the reflectance and iridescence of metallic surfaces.展开更多
In this study,we demonstrate a technique termed underwater persistent bubble assisted femtosecond laser ablation in liquids(UPB-fs-LAL)that can greatly expand the boundaries of surface micro/nanostructuring through la...In this study,we demonstrate a technique termed underwater persistent bubble assisted femtosecond laser ablation in liquids(UPB-fs-LAL)that can greatly expand the boundaries of surface micro/nanostructuring through laser ablation because of its capability to create concentric circular macrostructures with millimeter-scale tails on silicon substrates.Long-tailed macrostructures are composed of layered fan-shaped(central angles of 45°–141°)hierarchical micro/nanostructures,which are produced by fan-shaped beams refracted at the mobile bubble interface(.50°light tilt,referred to as the vertical incident direction)during UPB-fs-LAL line-by-line scanning.Marangoni flow generated during UPB-fs-LAL induces bubble movements.Fast scanning(e.g.1mms−1)allows a long bubble movement(as long as 2mm),while slow scanning(e.g.0.1mms−1)prevents bubble movements.When persistent bubbles grow considerably(e.g.hundreds of microns in diameter)due to incubation effects,they become sticky and can cause both gas-phase and liquidphase laser ablation in the central and peripheral regions of the persistent bubbles.This generates low/high/ultrahigh spatial frequency laser-induced periodic surface structures(LSFLs/HSFLs/UHSFLs)with periods of 550–900,100–200,40–100 nm,which produce complex hierarchical surface structures.A period of 40 nm,less than 1/25th of the laser wavelength(1030 nm),is the finest laser-induced periodic surface structures(LIPSS)ever created on silicon.The NIR-MIR reflectance/transmittance of fan-shaped hierarchical structures obtained by UPB-fs-LAL at a small line interval(5μm versus 10μm)is extremely low,due to both their extremely high light trapping capacity and absorbance characteristics,which are results of the structures’additional layers and much finer HSFLs.In the absence of persistent bubbles,only grooves covered with HSFLs with periods larger than 100 nm are produced,illustrating the unique attenuation abilities of laser properties(e.g.repetition rate,energy,incident angle,etc)by persistent bubbles with different curvatures.This research represents a straightforward and cost-effective approach to diversifying the achievable hierarchical micro/nanostructures for a multitude of applications.展开更多
For a clean and sustainable society,there is an urgent demand for renewable energy with net‐zero emissions due to fossil fuels limited resources and irreversible environmental impact.Hydrogen has the unrivaled potent...For a clean and sustainable society,there is an urgent demand for renewable energy with net‐zero emissions due to fossil fuels limited resources and irreversible environmental impact.Hydrogen has the unrivaled potential to replace fossil fuels due to its high gravimetric energy density,abundant sources(H_(2)O),and environmental friendliness.However,its low volumetric energy density causes significant challenges,inspiring major efforts to develop chemical‐based storage alternatives.Solid‐state hydrogen storage in materials has substantial potential for fulfilling the practical requirements and is recognized as a potential candidate due to their properties tuning more independently.However,hydrogen's stable thermodynamics and sluggish kinetics are the bottleneck to its widespread applications.To explore the kinetic and thermodynamic barriers in the fundamentals of hydrogen storage materials,this review will provide promising information for researchers to gain detailed knowledge about hydrogen storage energy applications and find new routes for materials engineering with tuned properties.This will further attract a wider scientific community and intend to understand the innovative concepts and strategies developed and to employ them in tailoring hydrogen storage materials'kinetic and thermodynamic properties.Recent advances in nanostructuring,nanoconfinement with in situ catalysts,and host/vip stress/strain engineering have the potential to propel the prospects of tailoring the hydrogen storage materials properties at the nanoscale with several promising directions and strategies that could lead to the next generation of solid‐state hydrogen storage practical applications.展开更多
To date,nanostructuring through plastic deformation has rarely been reported in biodegradable zinc(Zn)based alloys that have great potential in load-bearing conditions.Here,typical high-strength Zn-Li-based alloys wer...To date,nanostructuring through plastic deformation has rarely been reported in biodegradable zinc(Zn)based alloys that have great potential in load-bearing conditions.Here,typical high-strength Zn-Li-based alloys were subjected to SPD processes,including equal channel angular pressing(ECAP)and high-pressure torsion(HPT),to achieve nanostructured microstructures.The effects of SPD on the microstructures,mechanical properties,and corrosion behaviors were generally investigated.The two SPD routes resulted in totally different microstructures.ECAPed samples processed at 150℃ exhibited a complicated multilevel structure(nm toμm)with mixed Zn equiaxed grains and lamellar-like eutectoid regions(Zn+α-LiZn_(4)),and HPTed ones(25℃)possessed a fully dynamically recrystallized(DRXed)microstructure with an average grain size below 0.4μm.The tensile strength of the SPD samples could reach 500 MPa.Meanwhile,HPTed samples exhibited extraordinary fracture elongations higher than 100%,because of a different grain boundary sliding deformation mechanism.HPTed samples and ECAPed samples displayed different corrosion patterns,and the former exhibited a much higher corrosion rate in Hank's solution,possibly due to the accelerated corrosion at grain boundaries.In summary,SPD is an efficient way to refine the microstructure of biodegradable Zn-based alloys,possibly improving their performances and clinical applications.展开更多
The strength of traditional Al-Mg alloys primarily depends on cold deformation and increasing Mg content,but it can become susceptible to stress corrosion cracking(SCC)when the Mg content is high(>3 wt.%).Simultane...The strength of traditional Al-Mg alloys primarily depends on cold deformation and increasing Mg content,but it can become susceptible to stress corrosion cracking(SCC)when the Mg content is high(>3 wt.%).Simultaneous optimizing strength and SCC resistance in Al-Mg alloys is challenging.This study introduces a nanostructured Al-10Mg(10 wt.%)alloy with improved strength and SCC resistance by dynamic plastic deformation and optimized annealing.The as-deformed sample exhibits a nano-scaled lamellar structure.With rising annealing temperatures,structure size of the alloy increases while dislocation density decreases,transitioning lamellar to equiaxed grains.Nanostructured Al-10Mg alloys annealed at 250°C exhibit superior mechanical properties and reduced SCC susceptibility at sensitization state.The high fraction of low-angle grain boundaries with a reduction in dislocation density can effectively suppress the nucleation and growth of grain boundary precipitates(GBPs)during sensitization,thereby maintaining a relatively low GBPs coverage.The results provide guidance for designing Al-Mg alloys that are stronger and more resistant to SCC with higher Mg content.展开更多
The intermetallic compounds based on the tetragonal ThMn_(12) prototype crystal structure have exhibited great potential as advanced rare-earth-lean permanent magnets due to their excellent intrinsic magnetic properti...The intermetallic compounds based on the tetragonal ThMn_(12) prototype crystal structure have exhibited great potential as advanced rare-earth-lean permanent magnets due to their excellent intrinsic magnetic properties.However,the trade-off between the phase stability and the magnetic performance is often encountered in the ThMn_(12)-type magnets.This work was focused on the effects of V doping and nanos-tructuring on the phase stability and magnetic properties of ThMn_(12)-type Sm-Co-based magnets.Novel SmCo_(12)-based nanocrystalline alloys with the SmCo_(12) main phase were prepared for the first time.The prepared alloys from the optimal design achieved obviously higher coercivity than the isotropic SmFe_(12)-based alloys,together with comparable performance of other magnetic features.The enhancement in the coercivity was ascribed to the pinning of domain walls by the nanocrystalline grain boundaries and stacking faults.First-principles calculations and magnetic structure analysis disclosed that V substitution can stabilize the SmCo_(12) lattice and elevate its magnetocrystalline anisotropy.This study provides a new approach to developing stabilized metastable structured rare-earth-lean alloys with high magnetic per-formance.展开更多
Nanostructures have drawn great attentions for functional device applications. Among the various techniques developed for fabricating arrayed nanostructures of functional materials, nanostructuring technique with poro...Nanostructures have drawn great attentions for functional device applications. Among the various techniques developed for fabricating arrayed nanostructures of functional materials, nanostructuring technique with porous anodic aluminum oxide （AAO） membrane as templates becomes more attractive owing to the superior geometrical characteristics and low-cost preparation process. In this mini review, progress about functional we summarize our recent nanostructuring based on perfectly-ordered AAO membrane to prepare perfectly- ordered nanostructure arrays of functional materials toward constructing high-performance energy conversion and storage devices. By employing the perfectly-ordered AAO membrane as templates, arrayed nanostructures in the form ofnanodot, nanorod, nanotube and nanopore have been synthesized over a large area. These as-obtained nanostructure arrays have large specific surface area, high regularity, large-scale implementation, and tunable nanos- cale features. All these advanced features enable them to be of great advantage for the performance improvement of energy conversion and storage devices, including photo- electrochemical water splitting cells, supercapacitors, and batteries, etc.展开更多
Inscribing functional micro-nano-structures in transparent dielectrics enables constructing all-inorganic photonic devices with excellent integration,robustness,and durability,but remains a great challenge for convent...Inscribing functional micro-nano-structures in transparent dielectrics enables constructing all-inorganic photonic devices with excellent integration,robustness,and durability,but remains a great challenge for conventional fabrication techniques.Recently,ultrafast laser-induced self-organization engineering has emerged as a promising rapid prototyping platform that opens up facile and universal approaches for constructing various advanced nanophotonic elements and attracted tremendous attention all over the world.This paper summarizes the history and important milestones in the development of ultrafast laser-induced self-organized nanostructuring(ULSN)in transparent dielectrics and reviews recent research progresses by introducing newly reported physical phenomena,theoretical mechanisms/models,regulation techniques,and engineering applications,where representative works related to next-generation light manipulation,data storage,optical detecting are discussed in detail.This paper also presents an outlook on the challenges and future trends of ULSN,and important issues merit further exploration.展开更多
The poor surface conditions and osseointegration capacity of 3D printed Ti6Al4V implants(3DPT)significantly influence their performance as orthopedic and dental implants.In this work,we creatively introduce a one-step...The poor surface conditions and osseointegration capacity of 3D printed Ti6Al4V implants(3DPT)significantly influence their performance as orthopedic and dental implants.In this work,we creatively introduce a one-step femtosecond laser treatment to improve the surface conditions and osteointegration.The surface characterization,mechanical properties,corrosion resistance,and biological responses were investigated.These results found that femtosecond laser eliminated defects like embedded powders and superficial cracks while forming the nano cones-like structures surface on 3DPT,leading to enhanced osseointegration,anti-corrosion,and anti-fatigue performance.Molecular dynamics simulations revealed the ablation removal mechanism and the formation of nano cone-like structures.These findings were further supported by the in vivo studies,showing that the FS-treated implants had superior bone-implant contact and osseointegration.Hence,the one-step femtosecond laser method is regarded as a promising surface modification method for improving the functional performance of Ti-based orthopedic implants.展开更多
For the development of high-performance metallic glasses,enhancing their stability against viscous flow and crystallization is a primary objective.Vapor deposition or prolonged annealing is an effective method to impr...For the development of high-performance metallic glasses,enhancing their stability against viscous flow and crystallization is a primary objective.Vapor deposition or prolonged annealing is an effective method to improve glass stability,shown by increased glass transition temperature(Tg)and crystallization temperature(Tx).This contributes to the development of ultra-stable metallic glasses.Herein,we demonstrate that modulating the quenching temperature can also produce ultra-stable metallic glasses,as evidenced by an increase in Tx of 17-30 K in Cu-based metallic glasses.By modulating the quenching temperature,separated primary phases,secondary phases,and even nano-oxides can be obtained in the metallic glasses.Notably,metastable phases such as Cu-rich precipitates arising from secondary phase separation play a crucial role in enhancing glass stability.However,the enhancement of the stability of the glass has only a negligible effect on its mechanical properties.This study implies that different melt thermodynamic states generated by liquid-liquid separation and transition collectively determine the frozen-in glass structure.The results of this study will be helpful for the development of ultra-stable bulk glasses.展开更多
基金supported by grants from the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Major/key program(No.23M1060280)the Fundamental Research Funds for the Central Universities(No.2232024D-34 and No 2232023A-10).
文摘Magnesium(Mg)alloys are promising candidates for biodegradable implants and medical devices due to their biocompatibility,mechanical properties,and ability to degrade in vivo,thereby eliminating the need for secondary removal surgeries[1,2].However,their clinical adoption is hindered by rapid corrosion in physiological environments[3–5].Due to the high chemical reactivity of magnesium substrates and the inability of primary corrosion degradation products to form ideal protective layers,no effective scientific guidance has yet been identified from fundamental material science to address the rapid degradation of bare Mg[6–8].Surface modification strategies equivalently create new materials wrapped in a matrix,which can thus be extensively explored to enhance the corrosion resistance of Mg alloys while endowing them with tailored biological functionalities[9,10].
文摘Magnesium-based hydrogen storage materials are gaining significant attention due to their high hydrogen storage capacity and abundant availability.However,they encounter challenges,including slow hydrogen absorption and desorption kinetics and elevated operating temperatures.To address these issues,researchers have employed two main strategies:nanostructuring and the introduction of catalysts.This review provides a comprehensive overview of recent advancements in the modification of MgH_(2),emphasizing the impact of nanostructuring on enhancing hydrogen storage performance.It also examines the role of various catalysts,including carbon-based materials,transition metals and alloys,their oxides and halides,and composites,in improving hydrogen absorption and desorption characteristics.Studies indicate that these modifications can substantially lower the hydrogen absorption and desorption temperatures while enhancing kinetic performance.Furthermore,the effectiveness of catalysts is influenced by their type,dispersion,and interaction with magnesium-based materials and the catalytic mechanism,thereby elucidating the underlying catalytic mechanisms.The review concludes by discussing the current challenges and future directions in this field,aiming to provide theoretical insights for the practical application of magnesium-based hydrogen storage materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A2054,52273285,52061009,52262032)the National Key Research and Development Program of China(No.2022YFE0119100)the Guangxi Science and Technology Planning Project(Grant No.AD21220056).
文摘P-type Mg_(3)Sb_(2)-based Zintls have attracted considerable interest in the thermoelectric(TE)field due to their environmental friendliness and low cost.However,compared to their n-type counterparts,they show relatively low TE performance,limiting their application in TE devices.In this work,we simultaneously introduce Bi alloying at Sb sites and Ag doping at Mg sites into the Mg_(3)Sb_(2)to coopera-tively optimize the electrical and thermal properties for the first time,acquiring the highest ZT value of∼0.85 at 723 K and a high average ZT of 0.39 in the temperature range of 323-723 K in sample Mg_(2.94)Ag_(0.06)Sb_(1.9)Bi_(0.1).The first-principle calculations show that the codoping of Ag and Bi can shift the Fermi level into the valence band and narrow the band gap,resulting in the increased carrier concentration from 3.50×10^(17)cm^(-3)in the reference Mg 3 Sb 0.9 Bi 0.1 to∼7.88×10^(19)cm^(-3)in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.As a result,a remarkable power factor of∼778.9μW m^(-1)K^(-2)at 723 K is achieved in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.Meanwhile,a low lattice thermal conductivity of∼0.48 W m^(-1)K^(-1)at 723 K is also obtained with the help of phonon scattering at the distorted lattice,point defects,and nano-precipitates in sample Mg 2.94 Ag 0.06 Sb 0.9 Bi 0.1.The synergistic effect of using the multi-element co-doping/-alloying to optimize electrical properties in Mg_(3)Sb_(2)holds promise for further improving the TE performance of Zintl phase materials or even others.
基金financial support from MINECO through NEXMAG(M-era.Net,PCIN-2015-126)and 3D-MAGNETOH(MAT2017-89960-R)projectsfrom the Regional Government of Madrid through the NANOMAGCOST(P2018/NMT-4321)projectIMDEA Nanociencia is supported by the"Severo Ochoa"Programme for Centres of Excellence in R&D,MINECO(SEV-2016-0686).
文摘An unprecedentedly short milling time of 30 s was applied to gas-atomized MnAl powder in order to develop permanent magnet properties and,in particular,coercivity.It is shown that such a short processing time followed by annealing results in efficient nanostructuring and controlled phase transformation.The defects resulting from the microstrain induced during milling,together with the creation of the bphase during post-annealing,act as pinning centers resulting in an enhanced coercivity.This study shows the importance of finding a balance between the formation of the ferromagnetic s-MnAl phase and the bphase in order to establish a compromise between magnetization and coercivity.A coercivity as high as 4.2 kOe(1 Oe=79.6 A·m^-1)was obtained after milling(30 s)and annealing,which is comparable to values previously reported in the literature for milling times exceeding 20 h.This reduction of the postannealing temperature by 75℃ for the as-milled powder and a 2.5-fold increase in coercivity,while maintaining practically unchanged the remanence of the annealed gas-atomized material,opens a new path for the synthesis of isotropic MnAl-based powder.
文摘In this review we consider the development of optical near-field imaging and nanostructuring by means of laser ablation since its early stages around the turn of the century.The interaction of short,intense laser pulses with nanoparticles on a surface leads to laterally tightly confined,strongly enhanced electromagnetic fields below and around the nano-objects,which can easily give rise to nanoablation.This effect can be exploited for structuring substrate surfaces on a length scale well below the diffraction limit,one to two orders smaller than the incident laser wavelength.We report on structure formation by the optical near field of both dielectric and metallic nano-objects,the latter allowing even stronger and more localized enhancement of the electromagnetic field due to the excitation of plasmon modes.Structuring with this method enables one to nanopattern large areas in a one-step parallel process with just one laser pulse irradiation,and in the course of time various improvements have been added to this technique,so that also more complex and even arbitrary structures can be produced by means of nanoablation.The near-field patterns generated on the surface can be read out with high resolution techniques like scanning electron microscopy and atomic force microscopy and provide thus a valuable tool-in conjunction with numerical calculations like finite difference time domain(FDTD)simulations-for a deeper understanding of the optical and plasmonic properties of nanostructures and their applications.
文摘23K2O·27Nb2O5·50SiO 2（KNS）,13K2O·10Na2O·27Nb2O5·50SiO 2（KNaNS） and 15K2O·12Li2O·27Nb2O5·46SiO2（KLiNS） transparent glasses were synthesized by melt-quenching technique,and studied by differential thermal analysis（DTA）,X-ray diffraction（XRD） and high-resolution transmission electron microscopy（HRTEM） to reveal the effect of the devitrification behaviour on transparent nanostructure.Just above the glass transition temperature T g in the KNS glass,an unidentified phase was formed,while in KNaNS and KLiNS,mixed-alkali niobate phases with tungsten bronze structure were obtained by bulk crystallization.Heat treatments at T g performed on the KNS glass resulted in the transparent nanostructure with second order harmonic generation（SHG） activity.Heat treatment for 10 h on KNaNS and KLiNS decreased the first DTA exothermic peaks（at least 24C）,indicating the bulk nucleation,which was confirmed by the DTA in comparison with the powdered as-quenched samples.KNaNS and KLiNS showed similar XRD profiles as the K3Li2Nb5O15 crystal with the five most intense peaks at 22.7,29.4,32.3,46.3 and 52.0 deg.HRTEM micrograph showed clear-cut nano-sized circular domains and spherical nanocrystals dispersed into the amorphous matrix.
基金Funded by the National Basic Research Program of China (2007CB607501)
文摘Preparation and thermoelectric properties of nanostructured n-type Mg2Si bulk materials were reported. Nanosized Mg2Si powder was obtained by mechanical milling of the microsized Mg2Si powder prepared by solid-state reaction. The bulk materials with 30 nm and 5 μm were prepared by spark plasma sintering of the nanosized and microsized Mg2Si powder, respectively. Both the samples show n-type conduction and the Seebeck coefficient of the sintered samples increase determinately with the grain size decrease from 5 μm to 30 nm. On the other hand, the electrical and thermal conductivity decrease with the decrease of grain size. Accordingly, decreasing their grain size increases their thermoelectric-figure-of-merit. A maximum thermoelectric figure of merit of 0.36 has been obtained for the nanostuctured Mg2Si sample at 823 K, which is 38% higher than that of microsized Mg2Si bulk materials and higher than results of other literatures. It could be expected that the properties of the nanocomposites could be further improved by doping optimization.
文摘Self-organization processes in semiconductor materials on the example of nanostructuring of por-Si at long anodic etching of p-type Si in the electrolyte with internal source of the current are shown. In conditions of a “soft” etching of the Si point defects are formed and in the subsequently occurs their spatial-temporal ordering. This leads to the ordering pores and the nanostructuring of por-Si. Self-organization mechanism of Si nanocrystallites islets is described by the effects of the elastically-deformative, defectively-deformative and capillary-fluctuation forces.
基金support from the National Key Research&Development Program(2022YFB3803700)of ChinaNational Natural Science Foundation(No.52171186)financial support from the Center of Hydrogen Science,Shanghai Jiao Tong University。
文摘With the depletion of fossil fuels and global warming,there is an urgent demand to seek green,low-cost,and high-efficiency energy resources.Hydrogen has been considered as a potential candidate to replace fossil fuels,due to its high gravimetric energy density(142 MJ kg^(-1)),high abundance(H_(2)O),and environmentalfriendliness.However,due to its low volume density,effective and safe hydrogen storage techniques are now becoming the bottleneck for the"hydrogen economy".Under such a circumstance,Mg-based hydrogen storage materials garnered tremendous interests due to their high hydrogen storage capacity(~7.6 wt%for MgH_(2)),low cost,and excellent reversibility.However,the high thermodynamic stability(ΔH=-74.7 kJ mol^(-1)H_(2))and sluggish kinetics result in a relatively high desorption temperature(>300℃),which severely restricts widespread applications of MgH_(2).Nano-structuring has been proven to be an effective strategy that can simultaneously enhance the ab/de-sorption thermodynamic and kinetic properties of MgH_(2),possibly meeting the demand for rapid hydrogen desorption,economic viability,and effective thermal management in practical applications.Herein,the fundamental theories,recent advances,and practical applications of the nanostructured Mg-based hydrogen storage materials are discussed.The synthetic strategies are classified into four categories:free-standing nano-sized Mg/MgH_(2)through electrochemical/vapor-transport/ultrasonic methods,nanostructured Mg-based composites via mechanical milling methods,construction of core-shell nano-structured Mg-based composites by chemical reduction approaches,and multi-dimensional nano-sized Mg-based heterostructure by nanoconfinement strategy.Through applying these strategies,near room temperature ab/de-sorption(<100℃)with considerable high capacity(>6 wt%)has been achieved in nano Mg/MgH_(2)systems.Some perspectives on the future research and development of nanostructured hydrogen storage materials are also provided.
文摘The effect of rolling to a total effective strain of 2 at the liquid nitrogen temperature and subsequent natural and artificial aging on the structure and service properties of the pre-quenched hot-pressed 2024 aluminum alloy was investigated.Using optical and electron microscopy,and X-ray analysis,it was found that the cryorolling did not qualitatively change the type of the initial coarse-fibered microstructure,but produced a well-developed nanocell substructure inside fibers.Further aging led to decomposition of the preliminary supersaturated and work-hardened aluminum solid solution and precipitation of strengthening phases in the statically recovered and/or recrystallized matrix.As a result,the rolled and naturally aged alloy demonstrated the yield and ultimate tensile strengths(YS=590 MPa,UTS=640 MPа)much higher than those in the pressed andТ6-heat treated alloy at equal elongation to failure(El^6%).Artificial aging at a temperature less than conventional T6 route could provide the extra alloy strengthening and the unique balance of mechanical properties,involving enhanced strength(YS=610 MPa,UTS=665 MPа)and ductility(El^10%),and good static crack resistance(the specific works for crack formation and growth were 42 and 18 k J/m^2,respectively)and corrosion resistance(the intensity and depth of intercrystalline corrosion were 23%and 50μm,respectively).
文摘Femtosecond laser induced periodic surface structures(LIPSSs)are excellent biomimetic iridescent antireflective interfaces.In this work,we demonstrate the feasibility to develop tunable iridescent antireflective surfaces via simultaneous synthesis of functional metal-oxide nanomaterials,in situ deposition and hierarchical LIPSSs nanostructuring by means of femtosecond laser ablation(fs-LA)of tungsten(W)and molybdenum(Mo)in air.Adjusting the scanning interval from 1μm to 20μm allows the modulation of particle deposition rates on LIPSSs.Diminishing the scan interval enables a higher particle deposition rate,which facilitates the development of better UV-to-MIR ultrabroadband antireflective surfaces with a less pronounced iridescence.Through comparing the reflectance of hierarchical LIPSSs with different densities of loosely/tightly deposited particles,it is found that the deposited WO_(x)and MoO_(x)particle aggregates have high UV-to-MIR ultrabroadband absorbance,especially extraordinary in the MIR range.Loosely deposited particles which self-assembly into macroporous structures outperform tightly deposited particles for ultrabroadband antireflective applications.The presence of loosely deposited MoO_(x)and WO_(x)particle absorbers can cause up to 80%and 60%enhancement of antireflectance performances as compared to the tightly particle deposited LIPSSs samples.One stone of"fs-LA technique"with three birds of(particle generation,in situ deposition and LIPSS hierarchical nanostructuring)presented in this work opens up new opportunities to tune the reflectance and iridescence of metallic surfaces.
文摘In this study,we demonstrate a technique termed underwater persistent bubble assisted femtosecond laser ablation in liquids(UPB-fs-LAL)that can greatly expand the boundaries of surface micro/nanostructuring through laser ablation because of its capability to create concentric circular macrostructures with millimeter-scale tails on silicon substrates.Long-tailed macrostructures are composed of layered fan-shaped(central angles of 45°–141°)hierarchical micro/nanostructures,which are produced by fan-shaped beams refracted at the mobile bubble interface(.50°light tilt,referred to as the vertical incident direction)during UPB-fs-LAL line-by-line scanning.Marangoni flow generated during UPB-fs-LAL induces bubble movements.Fast scanning(e.g.1mms−1)allows a long bubble movement(as long as 2mm),while slow scanning(e.g.0.1mms−1)prevents bubble movements.When persistent bubbles grow considerably(e.g.hundreds of microns in diameter)due to incubation effects,they become sticky and can cause both gas-phase and liquidphase laser ablation in the central and peripheral regions of the persistent bubbles.This generates low/high/ultrahigh spatial frequency laser-induced periodic surface structures(LSFLs/HSFLs/UHSFLs)with periods of 550–900,100–200,40–100 nm,which produce complex hierarchical surface structures.A period of 40 nm,less than 1/25th of the laser wavelength(1030 nm),is the finest laser-induced periodic surface structures(LIPSS)ever created on silicon.The NIR-MIR reflectance/transmittance of fan-shaped hierarchical structures obtained by UPB-fs-LAL at a small line interval(5μm versus 10μm)is extremely low,due to both their extremely high light trapping capacity and absorbance characteristics,which are results of the structures’additional layers and much finer HSFLs.In the absence of persistent bubbles,only grooves covered with HSFLs with periods larger than 100 nm are produced,illustrating the unique attenuation abilities of laser properties(e.g.repetition rate,energy,incident angle,etc)by persistent bubbles with different curvatures.This research represents a straightforward and cost-effective approach to diversifying the achievable hierarchical micro/nanostructures for a multitude of applications.
基金supported by the Embassy of the People's Republic of China in Malaysia(EENG/0045)funded by Xiamen University Malaysia Investigatorship Grant(Grant no:IENG/0038)Xiamen University Malaysia Research Fund(ICOE/0001,XMUMRF/2021‐C8/IENG/0041,and XMUMRF/2025‐C15/IENG/0080).
文摘For a clean and sustainable society,there is an urgent demand for renewable energy with net‐zero emissions due to fossil fuels limited resources and irreversible environmental impact.Hydrogen has the unrivaled potential to replace fossil fuels due to its high gravimetric energy density,abundant sources(H_(2)O),and environmental friendliness.However,its low volumetric energy density causes significant challenges,inspiring major efforts to develop chemical‐based storage alternatives.Solid‐state hydrogen storage in materials has substantial potential for fulfilling the practical requirements and is recognized as a potential candidate due to their properties tuning more independently.However,hydrogen's stable thermodynamics and sluggish kinetics are the bottleneck to its widespread applications.To explore the kinetic and thermodynamic barriers in the fundamentals of hydrogen storage materials,this review will provide promising information for researchers to gain detailed knowledge about hydrogen storage energy applications and find new routes for materials engineering with tuned properties.This will further attract a wider scientific community and intend to understand the innovative concepts and strategies developed and to employ them in tailoring hydrogen storage materials'kinetic and thermodynamic properties.Recent advances in nanostructuring,nanoconfinement with in situ catalysts,and host/vip stress/strain engineering have the potential to propel the prospects of tailoring the hydrogen storage materials properties at the nanoscale with several promising directions and strategies that could lead to the next generation of solid‐state hydrogen storage practical applications.
基金supported by the National Natural Science Foundation of China(Nos.U22A20121,52101283 and 52271243)the NSFC-RGC Joint Research Scheme(No.52361165619)+3 种基金The NSFC-RFBR Joint Research Scheme(No.82361138575)the Science and Technology Planning Project of Guangzhou(No.202201011454)the National Key R&D Program of China(Nos.2021YFC2400700 and 2021YFC2400704)the High-level Hospital Construction Project(No.KJ012019520).
文摘To date,nanostructuring through plastic deformation has rarely been reported in biodegradable zinc(Zn)based alloys that have great potential in load-bearing conditions.Here,typical high-strength Zn-Li-based alloys were subjected to SPD processes,including equal channel angular pressing(ECAP)and high-pressure torsion(HPT),to achieve nanostructured microstructures.The effects of SPD on the microstructures,mechanical properties,and corrosion behaviors were generally investigated.The two SPD routes resulted in totally different microstructures.ECAPed samples processed at 150℃ exhibited a complicated multilevel structure(nm toμm)with mixed Zn equiaxed grains and lamellar-like eutectoid regions(Zn+α-LiZn_(4)),and HPTed ones(25℃)possessed a fully dynamically recrystallized(DRXed)microstructure with an average grain size below 0.4μm.The tensile strength of the SPD samples could reach 500 MPa.Meanwhile,HPTed samples exhibited extraordinary fracture elongations higher than 100%,because of a different grain boundary sliding deformation mechanism.HPTed samples and ECAPed samples displayed different corrosion patterns,and the former exhibited a much higher corrosion rate in Hank's solution,possibly due to the accelerated corrosion at grain boundaries.In summary,SPD is an efficient way to refine the microstructure of biodegradable Zn-based alloys,possibly improving their performances and clinical applications.
基金financially supported by the National Natural Science Foundation of China(No.52171088).We thank X.Si for assistance in sample preparation.
文摘The strength of traditional Al-Mg alloys primarily depends on cold deformation and increasing Mg content,but it can become susceptible to stress corrosion cracking(SCC)when the Mg content is high(>3 wt.%).Simultaneous optimizing strength and SCC resistance in Al-Mg alloys is challenging.This study introduces a nanostructured Al-10Mg(10 wt.%)alloy with improved strength and SCC resistance by dynamic plastic deformation and optimized annealing.The as-deformed sample exhibits a nano-scaled lamellar structure.With rising annealing temperatures,structure size of the alloy increases while dislocation density decreases,transitioning lamellar to equiaxed grains.Nanostructured Al-10Mg alloys annealed at 250°C exhibit superior mechanical properties and reduced SCC susceptibility at sensitization state.The high fraction of low-angle grain boundaries with a reduction in dislocation density can effectively suppress the nucleation and growth of grain boundary precipitates(GBPs)during sensitization,thereby maintaining a relatively low GBPs coverage.The results provide guidance for designing Al-Mg alloys that are stronger and more resistant to SCC with higher Mg content.
基金supported by the National Key R&D Program of China(Nos.2021YFB3501502 and 2021YFB3501504).
文摘The intermetallic compounds based on the tetragonal ThMn_(12) prototype crystal structure have exhibited great potential as advanced rare-earth-lean permanent magnets due to their excellent intrinsic magnetic properties.However,the trade-off between the phase stability and the magnetic performance is often encountered in the ThMn_(12)-type magnets.This work was focused on the effects of V doping and nanos-tructuring on the phase stability and magnetic properties of ThMn_(12)-type Sm-Co-based magnets.Novel SmCo_(12)-based nanocrystalline alloys with the SmCo_(12) main phase were prepared for the first time.The prepared alloys from the optimal design achieved obviously higher coercivity than the isotropic SmFe_(12)-based alloys,together with comparable performance of other magnetic features.The enhancement in the coercivity was ascribed to the pinning of domain walls by the nanocrystalline grain boundaries and stacking faults.First-principles calculations and magnetic structure analysis disclosed that V substitution can stabilize the SmCo_(12) lattice and elevate its magnetocrystalline anisotropy.This study provides a new approach to developing stabilized metastable structured rare-earth-lean alloys with high magnetic per-formance.
文摘Nanostructures have drawn great attentions for functional device applications. Among the various techniques developed for fabricating arrayed nanostructures of functional materials, nanostructuring technique with porous anodic aluminum oxide （AAO） membrane as templates becomes more attractive owing to the superior geometrical characteristics and low-cost preparation process. In this mini review, progress about functional we summarize our recent nanostructuring based on perfectly-ordered AAO membrane to prepare perfectly- ordered nanostructure arrays of functional materials toward constructing high-performance energy conversion and storage devices. By employing the perfectly-ordered AAO membrane as templates, arrayed nanostructures in the form ofnanodot, nanorod, nanotube and nanopore have been synthesized over a large area. These as-obtained nanostructure arrays have large specific surface area, high regularity, large-scale implementation, and tunable nanos- cale features. All these advanced features enable them to be of great advantage for the performance improvement of energy conversion and storage devices, including photo- electrochemical water splitting cells, supercapacitors, and batteries, etc.
基金National Natural Science Foundation of China(Grant Nos.U20A20211,51902286,61905215,and 62005164)National Key R&D Program of China(No.2021YFB2800500)+1 种基金Key Research Project of Zhejiang LabChina Postdoctoral Science Foundation(2021M702799).
文摘Inscribing functional micro-nano-structures in transparent dielectrics enables constructing all-inorganic photonic devices with excellent integration,robustness,and durability,but remains a great challenge for conventional fabrication techniques.Recently,ultrafast laser-induced self-organization engineering has emerged as a promising rapid prototyping platform that opens up facile and universal approaches for constructing various advanced nanophotonic elements and attracted tremendous attention all over the world.This paper summarizes the history and important milestones in the development of ultrafast laser-induced self-organized nanostructuring(ULSN)in transparent dielectrics and reviews recent research progresses by introducing newly reported physical phenomena,theoretical mechanisms/models,regulation techniques,and engineering applications,where representative works related to next-generation light manipulation,data storage,optical detecting are discussed in detail.This paper also presents an outlook on the challenges and future trends of ULSN,and important issues merit further exploration.
基金supported by the National Natural Science Foundation of China(No.U21A2055),Natural Science Foundation of Tianjin of China(No.21JCQNJC01280)Tianjin Key R&D Program Beijing-Tianjin-Hebei Collaborative Innovation Project(No.22YFXTHZ00120).
文摘The poor surface conditions and osseointegration capacity of 3D printed Ti6Al4V implants(3DPT)significantly influence their performance as orthopedic and dental implants.In this work,we creatively introduce a one-step femtosecond laser treatment to improve the surface conditions and osteointegration.The surface characterization,mechanical properties,corrosion resistance,and biological responses were investigated.These results found that femtosecond laser eliminated defects like embedded powders and superficial cracks while forming the nano cones-like structures surface on 3DPT,leading to enhanced osseointegration,anti-corrosion,and anti-fatigue performance.Molecular dynamics simulations revealed the ablation removal mechanism and the formation of nano cone-like structures.These findings were further supported by the in vivo studies,showing that the FS-treated implants had superior bone-implant contact and osseointegration.Hence,the one-step femtosecond laser method is regarded as a promising surface modification method for improving the functional performance of Ti-based orthopedic implants.
基金supported by the National Natural Science Foundation of China(Nos.51827801,52371152,and 51971120).
文摘For the development of high-performance metallic glasses,enhancing their stability against viscous flow and crystallization is a primary objective.Vapor deposition or prolonged annealing is an effective method to improve glass stability,shown by increased glass transition temperature(Tg)and crystallization temperature(Tx).This contributes to the development of ultra-stable metallic glasses.Herein,we demonstrate that modulating the quenching temperature can also produce ultra-stable metallic glasses,as evidenced by an increase in Tx of 17-30 K in Cu-based metallic glasses.By modulating the quenching temperature,separated primary phases,secondary phases,and even nano-oxides can be obtained in the metallic glasses.Notably,metastable phases such as Cu-rich precipitates arising from secondary phase separation play a crucial role in enhancing glass stability.However,the enhancement of the stability of the glass has only a negligible effect on its mechanical properties.This study implies that different melt thermodynamic states generated by liquid-liquid separation and transition collectively determine the frozen-in glass structure.The results of this study will be helpful for the development of ultra-stable bulk glasses.
