Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosize...Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosized anatase TiO_(2) exposed(001)facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg^(2+)ion storage.First-principles calculations reveal that the diffusion energy barrier of Mg^(2+)on the(001)facet is significantly lower than those in the bulk phase and on(100)facet,and the adsorption energy of Mg^(2+)on the(001)facet is also considerably lower than that on(100)facet,which guarantees superior interfacial Mg^(2+)storage of(001)facet.Moreover,anatase TiO_(2) exposed(001)facet displays a significantly higher capacity of 312.9 mAh g^(−1) in Mg-Li dual-salt electrolyte compared to 234.3 mAh g^(−1) in Li salt electrolyte.The adsorption energies of Mg^(2+)on(001)facet are much lower than the adsorption energies of Li+on(001)facet,implying that the Mg^(2+)ion interfacial storage is more favorable.These results highlight that controlling the crystal facet of the nanocrystals effectively enhances the interfacial storage of multivalent ions.This work offers valuable guidance for the rational design of high-capacity storage systems.展开更多
The performance of Mg alloys is significantly influenced by the concentrations and solid solution behavior of the alloying elements.In this work,the solid solution behavior of 20 alloying elements in 190 ternary Mg al...The performance of Mg alloys is significantly influenced by the concentrations and solid solution behavior of the alloying elements.In this work,the solid solution behavior of 20 alloying elements in 190 ternary Mg alloy systems at 500℃are systematically investigated.The solid solution behavior of a set of two different alloying elements in Mg alloy systems are suggested to be classified into three categories:inclusivity,exclusivity and proportionality.Inclusivity classification indicates that the two alloying elements are inclusive inα-Mg,increasing the joint solubility of both elements.Exclusivity classification suggests that the two alloying elements have a low joint solid solubility inα-Mg,since they prefer to form stable second phases.For the proportionality classification,the solubility curve of the ternary Mg alloy systems is a straight line connecting the solubility points of the two sub-binary systems.The proposed classification theory was validated by key experiments and the calculation of formation energies.The interaction effects between alloying elements and the preference of formation of second phases are the main factors determining the solid solution behavior classifications.Based on the observed solid solution features of multi-component Mg alloys,principles for alloy design of different types of high-performance Mg alloys were proposed in this work.展开更多
A CaCO_(3)coating with good anticorrosion and adhesion performance was fabricated via ultrasound-assisted chemical conversion on AZ41 magnesium alloy,with a water-bath treated coating as a control.The coating formed o...A CaCO_(3)coating with good anticorrosion and adhesion performance was fabricated via ultrasound-assisted chemical conversion on AZ41 magnesium alloy,with a water-bath treated coating as a control.The coating formed on AZ41 mainly consists of an outer CaCO_(3)layer and an inner(Ca,Mg)CO_(3)layer.Surface characterizations were carried out to obtain the morphology and the chemical composition,mechanical tests were also adopted to assess the hardness and the adhesion of the coating prepared.Afterwards,the long-term corrosion resistance was investigated via electrochemical methods in the chloride-containing Portland cement system.Results show that the ultrasound-assisted coating exhibits higher mechanical properties.In addition,the corrosion resistance of the ultrasound-assisted coating is also higher than that of the bare AZ41 alloy and the water-bath treated coating.This could be due to the formation of a much more compact CaCO_(3)coating on AZ41 Mg alloy,which is mainly benefit from the assistance of the ultrasound.Ultrasound accelerates the nucleation of CaCO_(3)crystals and assists the removal of hydrogen bubbles.Additionally,corrosion mechanism was suggested and discussed for the CaCO_(3)coating.展开更多
Rechargeable magnesium batteries(RMBs)have attracted much attention due to the high theoretical capacity(3833 mAh cm−3)of magnesium metal negative electrode and abundant resources.However,the preparation of ultra-thin...Rechargeable magnesium batteries(RMBs)have attracted much attention due to the high theoretical capacity(3833 mAh cm−3)of magnesium metal negative electrode and abundant resources.However,the preparation of ultra-thin magnesium foils faces the problems of rolling difficulty and high processing cost,while the use of thick magnesium foils leads to low utilization of magnesium and reduces the energy density.To tackle the above problems,we successfully prepared ultra-thin magnesium foils based on electrolytic process and investigated the effect of different substrates.The magnesium foils prepared using Mo substrate have more uniform surface morphology and lower surface roughness,which is attributed to the lower magnesium nucleation overpotential of Mo substrate.Meanwhile,density functional theory calculations show that the adsorption energy of Mo on Mg is more negative,which is conducive to achieving uniform nucleation and deposition of Mg.The Mg deposition on Mo substrate undergoes the characteristic stages of transient nucleation,nucleus accretion,multidirectional heterotopic growth,and columnar crystal stacking,and ultimately the formation of a dense deposited layer.In addition,the prepared ultra-thin Mg foil with Mo substrate can stably cycle for 1000 h at 3 mA cm^(-2) with high utilization of 50% in the symmetric cell.This study develops a facile method for the preparation of ultra-thin Mg foils,which opens up a new path for developing high-performance ultra-thin negative electrodes for RMBs.展开更多
Magnesium ion batteries(MIBs)are a promising alternative to lithium-ion batteries,which suffer from the short cycling life and sluggish Mg^(2+)diffusion kinetics of cathodes.Nano morphologies are used to shorten Mg^(2...Magnesium ion batteries(MIBs)are a promising alternative to lithium-ion batteries,which suffer from the short cycling life and sluggish Mg^(2+)diffusion kinetics of cathodes.Nano morphologies are used to shorten Mg^(2+)diffusion path for diffusion kinetics acceleration,but the cycling life is still unsatisfactory.Herein,the anisotropy of layered V_(3)O_(7)·1.9H_(2)O nanobelts is utilized to stabilize their structure during discharging/charging.The V_(3)O_(7)·1.9H_(2)O nanobelts grow along the preponderant migration direction of Mg^(2+),and the resulted axial migration of Mg^(2+)enables the stress caused by Mg^(2+)insertion to be decentralized in large zone,thus improving the cycling stability of V_(3)O_(7)·1.9H_(2)O nanobelts.The inserted Mg^(2+)cations bond with O atoms in adjacent V3O8 layers of V_(3)O_(7)·1.9H_(2)O,further stablizing the layered structure.Meanwhile,the axial migration of Mg^(2+)significantly reduces the charge transfer resistance at electrode/electrolyte interface,which accelerates the Mg^(2+)diffusion kinetics.Thus,the symmetric RMB assembled from V_(3)O_(7)·1.9H_(2)O nanobelts exhibits an ultralong cycling life of 11,000 cycles at 4 A g^(-1),alongside a high specific capacity of 137 mAh g^(-1)at 0.05 A g^(-1).According to our knowledge,this ultralong cycling life surpasses those of reported full RMBs.This strategy provides insight into the design of cathode materials with improved cycling lives.展开更多
While early transition metal-based materials,such as MXene,has emerged as an efficient catalyst for the Mg-based hydrogen storage materials,their strong interaction with hydrogen resulted in the high hydrogen diffusio...While early transition metal-based materials,such as MXene,has emerged as an efficient catalyst for the Mg-based hydrogen storage materials,their strong interaction with hydrogen resulted in the high hydrogen diffusion barrier,hindering further improvement of catalytic activity.A MXene is characterized by rich anionic groups on its surface,significantly affecting electronic and catalytic functionalities.Using Nb_(2)CT_(x)as an example,we herein illustrate the critical role of anionic T_(x)defects on controlling hydrogen dissociation and diffusion processes in Mg-based hydrogen storage materials.The hydrogen desorption properties of MgH_(2)can be significantly enhanced by utilizing T_(x)controllable Nb_(2)CT_(x),and it can release 3.57 wt.%hydrogen within 10 min under 240℃with the reduced dehydrogenation activation barrier.It also realized stable de/hydrogenation reactions for at least 50 cycles.DFT studies combined with kinetic analysis revealed that the catalyst‒hydrogen interaction could be systematically controlled by optimizing surface T_(x)defect density,accelerating the hydrogen dissociation and diffusion processes at the same time.These results demonstrate that the T_(x)defects serve as the effective catalytically active centers of Nb_(2)CT_(x),offering a flexible catalyst design guideline.展开更多
High purity magnesium is not only an important basic raw material for semiconductor and electronics industries,but also a promising new generation of electrochemical energy storage materials and biomedical materials.I...High purity magnesium is not only an important basic raw material for semiconductor and electronics industries,but also a promising new generation of electrochemical energy storage materials and biomedical materials.Impurities in high-purity magnesium affect material properties,which has become the most critical factor restricting its application.However,accurate analysis of multiple ultra-trace impurity elements in high-purity magnesium is extremely challenging.In this paper,based on the synergistic effect of N_(2)O/H_(2) reaction gas mixture to eliminate spectral interference of inductively coupled plasma tandem mass spectrometry(ICP-MS/MS),a new strategy for the quantification of 45 ultra-trace impurity elements in high-purity magnesium was proposed.The results indicated that the limits of detection(LOD)were in the range of 0.02–18.5 ng L^(−1);the LODs of the challenging non-metallic elements Si and S were 18.5 and 12.2 ng L^(−1),respectively;and the LODs of all the other analytes were less than 10 ng L^(−1).Even under hot plasma conditions,LODs of alkali metal elements were also less than 5 ng L^(−1).The spike recovery of each analyte was 93.6%–107%,and the relative standard deviation(RSD)was 3.2%–6.9%,respectively.At a 95%level of confidence,no significant differences were found between the results obtained under the optimal conditions for the analyte with the developed method and the measurement results of SF-ICP-MS.The developed method indicated low LOD,high sample throughput,and complete interference elimination,demonstrating a new avenue for the rapid determination of ultra-trace elements in high-purity magnesium.展开更多
Magnesium-lithium hybrid batteries(MLHBs)have gained increasing attention due to their combined advantages of rapid ion insertion/extraction cathode and magnesium metal anode.Herein,Sn S_(2)-SPAN hybrid cathode with s...Magnesium-lithium hybrid batteries(MLHBs)have gained increasing attention due to their combined advantages of rapid ion insertion/extraction cathode and magnesium metal anode.Herein,Sn S_(2)-SPAN hybrid cathode with strong C-Sn bond and rich defects is ingeniously constructed to realize Mg^(2+)/Li^(+)co-intercalation.The physical and chemical double-confinement synergistic engineering of sulfurized polyacrylonitrile can suppress the agglomeration of Sn S_(2)nanoparticles and the volume expansion,simultaneously promote charge transfer and enhance structural stability.The introduced abundant sulfur vacancies provide more active sites for Mg^(2+)/Li^(+)co-intercalation.Meanwhile,the beneficial effects of rich sulfur defects and C-Sn bond on enhanced electrochemical properties are further evidenced by density-functional theory(DFT)calculations.Therefore,compared with pristine SnS_(2),SnS_(2)-SPAN cathode displays high specific capacity(218 m Ah g^(-1)at 0.5A g^(-1)over 700 cycles)and ultra-long cycling life(101 m Ah g^(-1)at 5 A g^(-1)up to 28,000 cycles).And a high energy density of 307 Wh kg^(-1)can be realized by the Sn S_(2)-SPAN//Mg pouch cell.Such elaborate and simple design supplies a reference for the exploitation of advanced cathode materials with excellent electrochemical properties for MLHBs.展开更多
The inherent thermodynamic and kinetic challenges of Mg/Mg H_(2) hydrogen storage materials pose significant obstacles to their development.Alloying has emerged as a highly promising strategy to overcome these challen...The inherent thermodynamic and kinetic challenges of Mg/Mg H_(2) hydrogen storage materials pose significant obstacles to their development.Alloying has emerged as a highly promising strategy to overcome these challenges.In this study,we synthesized a series of Mg_(93)-Ni_(7-x)-Si_(x)(x=0.4,1.6,5)ternary alloys through microstructure optimization and particle refinement using melting and high energy ball milling techniques.We systematically investigated the effects of varying Ni and Si content on the microstructure and hydrogen storage properties of Mg-Ni-Si alloys.The results demonstrate that variations in Ni and Si content leads to the formation of different types of intermetallic compounds within the alloys,thereby influencing their hydrogen storage properties.Among the tested alloys,Mg_(93)Ni_(2) Si_5 exhibits superior activation and hydrogen absorption properties.The enhanced hydrogenation performance can be attributed to the precipitation of the Mg_(2) Si phase resulting from increased Si content,as well as the refinement of the Mg_(2) Ni_(3) Si phase and the increase in eutectic structure Mg+Mg_(11)Ni_(12)Si_(10).Significantly,the increased intermetallic compounds provide a large number of sites and channels for the nucleation of hydrides as well as the diffusion of hydrogen.During the dehydrogenation process,Ni,serves as the predominant catalytic species,effectively promotes the dissociation of hydrogen and enhances the reaction kinetics.As a result,the hydrogen desorption of the hydrogenated Mg_(93)Ni_(6.6)Si_(0.4)alloy initiates at 180℃,with a reduced activation energy of 105.21 k J/mol.These findings underscore the synergistic and effective roles of Ni and Si elements in enhancing the hydrogen storage properties of Mg-based materials,thus supporting the development of economically viable and promising Mg-based solid-state hydrogen storage materials.展开更多
Frequent flood disasters caused by climate change may lead to tremendous economic and human losses along inland waterways.Emergency response and rescue vessels(ERRVs)play an essential role in minimizing losses and pro...Frequent flood disasters caused by climate change may lead to tremendous economic and human losses along inland waterways.Emergency response and rescue vessels(ERRVs)play an essential role in minimizing losses and protecting lives and property.However,the path planning of ERRVs has mainly depended on expert experiences instead of rational decision making.This paper proposes an improved artificial potential field(APF)algorithm to optimize the shortest path for ERRVs in the rescue process.To verify the feasibility of the proposed model,eight tests were carried out in two water areas of the Yangtze River.The results showed that the improved APF algorithm was efficient with fewer iterations and that the response time of path planning was reduced to around eight seconds.The improved APF algorithm performed better in the ERRV’s goal achievement,compared with the traditional algorithm.The path planning method for ERRVs proposed in this paper has theoretical and practical value in flood relief.It can be applied in the emergency management of ERRVs to accelerate flood management efficiency and improve capacity to prevent,mitigate,and relieve flood disasters.展开更多
Microstructure, electrical conductivity, and electromagnetic interference(EMI) shielding effectiveness(SE) of cast Mg-x Zn-y Y(x = 2–5, y = 1–10) alloys were systematically investigated to understand the effects of ...Microstructure, electrical conductivity, and electromagnetic interference(EMI) shielding effectiveness(SE) of cast Mg-x Zn-y Y(x = 2–5, y = 1–10) alloys were systematically investigated to understand the effects of Zn and Y additions on electrical conductivity and electromagnetic shielding effectiveness of the alloys.Experimental results indicate that the electrical conductivity and SE of the Mg-x Zn-y Y alloys decrease with Y/Zn ratio. Electrical conductivity is the main factor that affects the electromagnetic shielding properties and the variation tendency of electromagnetic shielding properties of the Mg-x Zn-y Y alloys is consistent with conductivity. Valence of Y and Zn atoms, configuration of extranuclear electron and volumetric difference are main reasons for the variations in the electrical conductivity. A high density of second phase and the formation of semi-continuous network structure can also improve the SE value at high frequencies.展开更多
High hydrogen absorption and desorption rates are two significant index parameters for the applications of hydrogen storage tanks.The analysis of the hydrogen absorption and desorption behavior using the isothermal ki...High hydrogen absorption and desorption rates are two significant index parameters for the applications of hydrogen storage tanks.The analysis of the hydrogen absorption and desorption behavior using the isothermal kinetic models is an efficient way to investigate the kinetic mechanism.Multitudinous kinetic models have been developed to describe the kinetic process.However,these kinetic models were de-duced based on some assumptions and only appropriate for specific kinetic measurement methods and rate-controlling steps(RCSs),which sometimes lead to confusion during application.The kinetic analysis procedures using these kinetic models,as well as the key kinetic parameters,are unclear for many researchers who are unfamiliar with this field.These problems will prevent the kinetic models and their analysis methods from revealing the kinetic mechanism of hydrogen storage alloys.Thus,this review mainly focuses on the summarization of kinetic models based on different kinetic measurement methods and RCSs for the chemisorption,surface penetration,diffusion of hydrogen,nucleation and growth,and chemical reaction processes.The analysis procedures of kinetic experimental data are expounded,as well as the effects of temperature,hydrogen pressure,and particle radius.The applications of the kinetic models for different hydrogen storage alloys are also introduced.展开更多
Magnesium(Mg)and its alloys present great potential to be extensively applied in different applications.However,the relatively poor resistance to corrosion and wear significantly restricts their applications in practi...Magnesium(Mg)and its alloys present great potential to be extensively applied in different applications.However,the relatively poor resistance to corrosion and wear significantly restricts their applications in practice.As one of strategies of surface treatment,micro-arc oxidation(MAO)process attracts a lot of attention,since it does not use neither expensive equipment,nor complicated manipulation.This review systematically discusses MAO mechanism and some typical models,which still need to be further developed to provide a better understanding and guide for future researchers.Subsequently,main influencing factors of MAO process are analyzed in detail.Further,some popular applications of MAO coatings are respectively reviewed,including biomedical application,decoration,thermal control,corrosion and wear resistance,and industrial applications in practice.The existing issues and future perspectives are finally discussed to further accelerate extensive applications of Mg alloys.展开更多
In this work,as-cast Mg-Ni-Y alloys were proposed to develop a feasible material for fracturing balls,and their mechanical performance and corrosion behavior were systematically investigated.Long period stacking order...In this work,as-cast Mg-Ni-Y alloys were proposed to develop a feasible material for fracturing balls,and their mechanical performance and corrosion behavior were systematically investigated.Long period stacking order(LPSO)phase was firstly introduced to improve both the mechanical properties and degradation rate of magnesium alloys.With the increase of LPSO phase,the compressive strength was improved significantly,while the elongation of the alloys decreased owing to the relatively brittle nature of LPSO phase.Due to the higher corrosion potential of LPSO phase,the LPSO phase can accelerate the corrosion process by providing more micro-couples.However,the LPSO phase would serve as the corrosion barrier between the corrosion medium and the matrix when the contents of LPSO phase are too high in Mg92.5Ni3Y4.5 and Mg87.5Ni5Y7.5 alloys.As-cast Mg97.5Ni1Y1.5 alloy with satisfactory mechanical properties and rapid degradation rate was successfully developed,exhibiting a high degradation rate of 6675 mm/a(93℃)in 3 wt.%KCl solution and a favorable ultimate compressive strength of 410 MPa.The degradation rate of Mg97.5Ni1Y1.5 alloy is 2-5 times of the current commercial magnesium alloy fracturing materials.展开更多
An efcient and simple in-situ growth strategy has been discovered for the preparation of highly reproducible and continuous symbiotic ZIF-8-based anticorrosion coating by using graphene oxide(GO)/Mg AlNO3layered doubl...An efcient and simple in-situ growth strategy has been discovered for the preparation of highly reproducible and continuous symbiotic ZIF-8-based anticorrosion coating by using graphene oxide(GO)/Mg AlNO3layered double hydroxides(G/LDHs) buffer layer as a new type of connecting carrier based on micro-arc oxide(MAO) coating of AZ31 magnesium alloy. The components of ZIF-8 were adsorbed and bounded to the surface of the G/LDHs buffer layer-modified substrates to promote the nucleation of ZIF-8,thus growing a phase-pure, uniform, and good symbiosis ZIF-8 membrane. ZIF-8 particles with different growth times compensate for the grain boundary defects of the G/LDHs coating precursor buffer layer to different degrees. The prepared ZIF-8-based coating has excellent stability and corrosion resistance. The results demonstrate that the G/LDHs buffer layer provides a new channel for the MOF-modified MAO substrate of AZ31 magnesium alloy. It also proves that it is feasible to build high-performance anticorrosive coatings with MOF materials.展开更多
Herein,we report the successful preparation of the FeCoNiCrMn high entropy alloy(HEA)loaded MgH_(2) and HEA’s effect on the hydrogen storage properties of Mg/MgH_(2).The HEA shows high catalytic activity toward hydro...Herein,we report the successful preparation of the FeCoNiCrMn high entropy alloy(HEA)loaded MgH_(2) and HEA’s effect on the hydrogen storage properties of Mg/MgH_(2).The HEA shows high catalytic activity toward hydrogen dissociation and recombination reaction,and successfully suppressed activation energy of dehydrogenation reaction from 151.9 to 90.2 kJ mol-1.Moreover,part of Co and Ni can react with Mg,and produce Mg_(2) Co/Mg_(2) CoH 5 and Mg_(2) Ni/Mg_(2) NiH_(4) during the hydrogen storage processes,further en-hancing dehydrogenation reaction through the“hydrogen pumping”mechanism.Asa result,the MgH_(2)-5 wt%HEA composite can release 5.6 wt%of H_(2) at 280℃ within 10 min,and absorb 5.5 wt%H_(2) within 0.5 min at 150℃.The loaded HEA shows robustness against particle aggregation,leading to stable re-versible hydrogen storage processes at least 50 times.These findings show the synergistic effects of HEA on Mg-based hydrogen storage materials,providing an additional degree of freedom for catalyst design.展开更多
The mechanical properties and bio-corrosion behaviors of as-extruded Mg-4Zn alloys after Sn addition were investigated,systemati-cally.A small amount of Sn addition to Mg-4Zn alloy slightly improved the mechanical pro...The mechanical properties and bio-corrosion behaviors of as-extruded Mg-4Zn alloys after Sn addition were investigated,systemati-cally.A small amount of Sn addition to Mg-4Zn alloy slightly improved the mechanical properties for solid solution strengthening,and significantly controlled the bio-corrosion rates.Sn participating in the outer layer film formation as SnO/SnO_(2)resisted the bio-corrosion proceeding.Especially,Mg-4Zn-1.5Sn alloy,with a weight loss rate of 0.45 mm/y and hydrogen evolution rate of 0.099 mL/cm^(2)/day,showed cytotoxicity grade of 0 to MC3T3-E1 cells.The perfect alliance of cytocompatibility,suitable mechanical properties and low bio-corrosion rate demonstrates that this Mg-4Zn-1.5Sn alloy is a promising biodegradable magnesium alloy for orthopedic implants.展开更多
The solid–liquid compound casting of Mg-AZ91D and Ti-TC4 alloys was developed by using pure Ni electro-deposited coating.The pouring temperatures of 660℃,690℃,720℃and 750℃were chosen to investigated the effects o...The solid–liquid compound casting of Mg-AZ91D and Ti-TC4 alloys was developed by using pure Ni electro-deposited coating.The pouring temperatures of 660℃,690℃,720℃and 750℃were chosen to investigated the effects of casting temperatures on microstructural evolution,properties,and fracture behaviors of Ni-coated TC4/AZ91D bimetals by the solid–liquid compound casting(SLCC).The scanning electron microscopy(SEM)and the energy dispersive spectroscopy(EDS)results showed that the interfacial zone mainly composed of nickel,Mg_(2)Ni and Mg-Al-Ni in the bimetals cast at 660℃.As the pouring temperature was increased to 750℃,the width of the interface zone,which mainly composed ofδ(Mg),Mg_(2)Ni,Mg-Al-Ni,Mg_(3)TiNi_(2) and Al_(3)Ni,gradually increased.The microhardness tests showed that the micro-hardness of the interface zone was smaller than that of TC4 substrate but larger than that of the cast AZ91D matrix.At the pouring temperature of 720℃,the Ni-coated TC4/AZ91D bimetals had the most typical homogeneous interface,which had granular Mg-Al-Ni ternary phase but no ribbon-like Al3Ni binary phase,and achieved the highest shear strength of 97.35MPa.Meanwhile,further fracture behavior analysis showed that most fracture failure of Ni-coated TC4/AZ91D bimetals occurred at the Mg_(2)Ni+δ(Mg)eutectic structure and Al_(3)Ni hard intermetallic.展开更多
The low-density magnesium(Mg)alloys are attractive for the application in aerospace,transportation and other weight-saving-required fields.The mechanical properties and corrosion properties of Mg alloys are the key-pr...The low-density magnesium(Mg)alloys are attractive for the application in aerospace,transportation and other weight-saving-required fields.The mechanical properties and corrosion properties of Mg alloys are the key-property issues for the wide application.It is surprising to find that the solid solution of alloying elements in theα-Mg phase can have multi-effects on the properties of Mg alloys,e.g.,solid solution strengthening,solid solution corrosion-resistance-enhancing,etc.Additionally,the alloy design theory of"solid solution strengthening and ductilizing"proposed by Pan and co-workers has attracted extensive attentions.It is promising that by selected proper multi-alloying-elements(with optimal ratio)solid solutioned in theα-Mg phase,the comprehensive properties of Mg alloys can be synergistically improved.In this work,the solid solution behavior of Mg alloys and the followed solid solution property-enhancing effects were reviewed.The mechanisms proposed recently by researchers for these solid solution property-enhancing behaviors were presented,and the related calculations and predictions were also described.It is shown the demonstrations of the fundamentals for the solid solution property-enhancing of Mg alloys,especially from the atomic inter-reaction aspects,still require elaborated characterization work and calculation work.Additionally,it could be expected that the multi-solute in Mg alloys can bring many possibilities,or,in another saying,"cocktail effects".With understanding the multi-solute interaction behavior and the corresponded solid solution property-enhancing effects,the good balanced high-performance Mg alloys can be developed.展开更多
The influence of Zn on the strain hardening of as-extruded Mg-x Zn(x = 1, 2, 3 and 4 wt%) magnesium alloys was investigated using uniaxial tensile tests at 10^(-3)s^(-1) at room temperature. The strain hardening rate,...The influence of Zn on the strain hardening of as-extruded Mg-x Zn(x = 1, 2, 3 and 4 wt%) magnesium alloys was investigated using uniaxial tensile tests at 10^(-3)s^(-1) at room temperature. The strain hardening rate,the strain hardening exponent and the hardening capacity were obtained from true plastic stress-strain curves. There were almost no second phases in the as-extruded Mg-Zn magnesium alloys. Average grain sizes of the four as-extruded alloys were about 17.8 μm. With increasing Zn content from 1 to 4 wt%, the strain hardening rate increased from 2850 MPa to 6810 MPa at(б-б_(0.2)) = 60 MPa, the strain hardening exponent n increased from 0.160 to 0.203, and the hardening capacity, Hc increased from 1.17 to 2.34.The difference in strain hardening response of these Mg-Zn alloys might be mainly caused by weaker basal texture and more solute atoms in the α-Mg matrix with higher Zn content.展开更多
基金supported by the National Key R&D Program of China(No.2023YFB3809500)the Fundamental Research Funds for the Central Universities(No.2024CDJXY003)+1 种基金the Venture&Innovation Support Program for Chongqing Overseas Returnees(cx2023087)The Chongqing Technology Innovation and Application Development Project(No.2024TIAD-KPX0003).
文摘Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosized anatase TiO_(2) exposed(001)facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg^(2+)ion storage.First-principles calculations reveal that the diffusion energy barrier of Mg^(2+)on the(001)facet is significantly lower than those in the bulk phase and on(100)facet,and the adsorption energy of Mg^(2+)on the(001)facet is also considerably lower than that on(100)facet,which guarantees superior interfacial Mg^(2+)storage of(001)facet.Moreover,anatase TiO_(2) exposed(001)facet displays a significantly higher capacity of 312.9 mAh g^(−1) in Mg-Li dual-salt electrolyte compared to 234.3 mAh g^(−1) in Li salt electrolyte.The adsorption energies of Mg^(2+)on(001)facet are much lower than the adsorption energies of Li+on(001)facet,implying that the Mg^(2+)ion interfacial storage is more favorable.These results highlight that controlling the crystal facet of the nanocrystals effectively enhances the interfacial storage of multivalent ions.This work offers valuable guidance for the rational design of high-capacity storage systems.
基金financially supported by National Natural Science Foundation of China(grant numbers:52171100,U20A20234)National Key R&D Program of China(grant number:2021YFB3701100)。
文摘The performance of Mg alloys is significantly influenced by the concentrations and solid solution behavior of the alloying elements.In this work,the solid solution behavior of 20 alloying elements in 190 ternary Mg alloy systems at 500℃are systematically investigated.The solid solution behavior of a set of two different alloying elements in Mg alloy systems are suggested to be classified into three categories:inclusivity,exclusivity and proportionality.Inclusivity classification indicates that the two alloying elements are inclusive inα-Mg,increasing the joint solubility of both elements.Exclusivity classification suggests that the two alloying elements have a low joint solid solubility inα-Mg,since they prefer to form stable second phases.For the proportionality classification,the solubility curve of the ternary Mg alloy systems is a straight line connecting the solubility points of the two sub-binary systems.The proposed classification theory was validated by key experiments and the calculation of formation energies.The interaction effects between alloying elements and the preference of formation of second phases are the main factors determining the solid solution behavior classifications.Based on the observed solid solution features of multi-component Mg alloys,principles for alloy design of different types of high-performance Mg alloys were proposed in this work.
基金the National Key Research and Development Program of China(Grant No.2021YFB3701100)the Natural Science Foundation Commission of China(Grant Nos.U20A20234and 51874062)+1 种基金Chongqing Foundation and Advanced Research Project(Grant No.cstc2019jcyj-zdxmX 0010)the Science and Technology Major Project of Shanxi Province(Grant No.20191102008)。
文摘A CaCO_(3)coating with good anticorrosion and adhesion performance was fabricated via ultrasound-assisted chemical conversion on AZ41 magnesium alloy,with a water-bath treated coating as a control.The coating formed on AZ41 mainly consists of an outer CaCO_(3)layer and an inner(Ca,Mg)CO_(3)layer.Surface characterizations were carried out to obtain the morphology and the chemical composition,mechanical tests were also adopted to assess the hardness and the adhesion of the coating prepared.Afterwards,the long-term corrosion resistance was investigated via electrochemical methods in the chloride-containing Portland cement system.Results show that the ultrasound-assisted coating exhibits higher mechanical properties.In addition,the corrosion resistance of the ultrasound-assisted coating is also higher than that of the bare AZ41 alloy and the water-bath treated coating.This could be due to the formation of a much more compact CaCO_(3)coating on AZ41 Mg alloy,which is mainly benefit from the assistance of the ultrasound.Ultrasound accelerates the nucleation of CaCO_(3)crystals and assists the removal of hydrogen bubbles.Additionally,corrosion mechanism was suggested and discussed for the CaCO_(3)coating.
基金supported by the National Natural Science Foundation of China(No.U2037601)the National Key Research and Development Program(No.2023YFB3809500)the Chongqing Technology Innovation and Application Development Project(No.CSTB2022TIAD-KPX0028).
文摘Rechargeable magnesium batteries(RMBs)have attracted much attention due to the high theoretical capacity(3833 mAh cm−3)of magnesium metal negative electrode and abundant resources.However,the preparation of ultra-thin magnesium foils faces the problems of rolling difficulty and high processing cost,while the use of thick magnesium foils leads to low utilization of magnesium and reduces the energy density.To tackle the above problems,we successfully prepared ultra-thin magnesium foils based on electrolytic process and investigated the effect of different substrates.The magnesium foils prepared using Mo substrate have more uniform surface morphology and lower surface roughness,which is attributed to the lower magnesium nucleation overpotential of Mo substrate.Meanwhile,density functional theory calculations show that the adsorption energy of Mo on Mg is more negative,which is conducive to achieving uniform nucleation and deposition of Mg.The Mg deposition on Mo substrate undergoes the characteristic stages of transient nucleation,nucleus accretion,multidirectional heterotopic growth,and columnar crystal stacking,and ultimately the formation of a dense deposited layer.In addition,the prepared ultra-thin Mg foil with Mo substrate can stably cycle for 1000 h at 3 mA cm^(-2) with high utilization of 50% in the symmetric cell.This study develops a facile method for the preparation of ultra-thin Mg foils,which opens up a new path for developing high-performance ultra-thin negative electrodes for RMBs.
基金supported by the National Natural Science Foundation of China(52222407).
文摘Magnesium ion batteries(MIBs)are a promising alternative to lithium-ion batteries,which suffer from the short cycling life and sluggish Mg^(2+)diffusion kinetics of cathodes.Nano morphologies are used to shorten Mg^(2+)diffusion path for diffusion kinetics acceleration,but the cycling life is still unsatisfactory.Herein,the anisotropy of layered V_(3)O_(7)·1.9H_(2)O nanobelts is utilized to stabilize their structure during discharging/charging.The V_(3)O_(7)·1.9H_(2)O nanobelts grow along the preponderant migration direction of Mg^(2+),and the resulted axial migration of Mg^(2+)enables the stress caused by Mg^(2+)insertion to be decentralized in large zone,thus improving the cycling stability of V_(3)O_(7)·1.9H_(2)O nanobelts.The inserted Mg^(2+)cations bond with O atoms in adjacent V3O8 layers of V_(3)O_(7)·1.9H_(2)O,further stablizing the layered structure.Meanwhile,the axial migration of Mg^(2+)significantly reduces the charge transfer resistance at electrode/electrolyte interface,which accelerates the Mg^(2+)diffusion kinetics.Thus,the symmetric RMB assembled from V_(3)O_(7)·1.9H_(2)O nanobelts exhibits an ultralong cycling life of 11,000 cycles at 4 A g^(-1),alongside a high specific capacity of 137 mAh g^(-1)at 0.05 A g^(-1).According to our knowledge,this ultralong cycling life surpasses those of reported full RMBs.This strategy provides insight into the design of cathode materials with improved cycling lives.
基金supported by Liuchuang Program of Chongqing Municipality(cx2022038)the Fundamental Research Funds for the Central Universities(2022CDJQY-013)the Graduate Research and Innovation Foundation of Chongqing,China(CYB22005).
文摘While early transition metal-based materials,such as MXene,has emerged as an efficient catalyst for the Mg-based hydrogen storage materials,their strong interaction with hydrogen resulted in the high hydrogen diffusion barrier,hindering further improvement of catalytic activity.A MXene is characterized by rich anionic groups on its surface,significantly affecting electronic and catalytic functionalities.Using Nb_(2)CT_(x)as an example,we herein illustrate the critical role of anionic T_(x)defects on controlling hydrogen dissociation and diffusion processes in Mg-based hydrogen storage materials.The hydrogen desorption properties of MgH_(2)can be significantly enhanced by utilizing T_(x)controllable Nb_(2)CT_(x),and it can release 3.57 wt.%hydrogen within 10 min under 240℃with the reduced dehydrogenation activation barrier.It also realized stable de/hydrogenation reactions for at least 50 cycles.DFT studies combined with kinetic analysis revealed that the catalyst‒hydrogen interaction could be systematically controlled by optimizing surface T_(x)defect density,accelerating the hydrogen dissociation and diffusion processes at the same time.These results demonstrate that the T_(x)defects serve as the effective catalytically active centers of Nb_(2)CT_(x),offering a flexible catalyst design guideline.
基金supported by the Natural Science Foundation of China(52171103 and 21975289).
文摘High purity magnesium is not only an important basic raw material for semiconductor and electronics industries,but also a promising new generation of electrochemical energy storage materials and biomedical materials.Impurities in high-purity magnesium affect material properties,which has become the most critical factor restricting its application.However,accurate analysis of multiple ultra-trace impurity elements in high-purity magnesium is extremely challenging.In this paper,based on the synergistic effect of N_(2)O/H_(2) reaction gas mixture to eliminate spectral interference of inductively coupled plasma tandem mass spectrometry(ICP-MS/MS),a new strategy for the quantification of 45 ultra-trace impurity elements in high-purity magnesium was proposed.The results indicated that the limits of detection(LOD)were in the range of 0.02–18.5 ng L^(−1);the LODs of the challenging non-metallic elements Si and S were 18.5 and 12.2 ng L^(−1),respectively;and the LODs of all the other analytes were less than 10 ng L^(−1).Even under hot plasma conditions,LODs of alkali metal elements were also less than 5 ng L^(−1).The spike recovery of each analyte was 93.6%–107%,and the relative standard deviation(RSD)was 3.2%–6.9%,respectively.At a 95%level of confidence,no significant differences were found between the results obtained under the optimal conditions for the analyte with the developed method and the measurement results of SF-ICP-MS.The developed method indicated low LOD,high sample throughput,and complete interference elimination,demonstrating a new avenue for the rapid determination of ultra-trace elements in high-purity magnesium.
基金financially supported by the National Key R&D Program of China(No.2023YFB3809500)National Natural Science Foundation of China(Grant No.51931006,52272240 and U22A20118)+2 种基金the Fundamental Research Funds for the Central Universities of China(Xiamen University:No.20720220074)Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(HRTP-[2022]-22)the“Double-First Class”Foundation of Materials Intelligent Manufacturing Discipline of Xiamen University。
文摘Magnesium-lithium hybrid batteries(MLHBs)have gained increasing attention due to their combined advantages of rapid ion insertion/extraction cathode and magnesium metal anode.Herein,Sn S_(2)-SPAN hybrid cathode with strong C-Sn bond and rich defects is ingeniously constructed to realize Mg^(2+)/Li^(+)co-intercalation.The physical and chemical double-confinement synergistic engineering of sulfurized polyacrylonitrile can suppress the agglomeration of Sn S_(2)nanoparticles and the volume expansion,simultaneously promote charge transfer and enhance structural stability.The introduced abundant sulfur vacancies provide more active sites for Mg^(2+)/Li^(+)co-intercalation.Meanwhile,the beneficial effects of rich sulfur defects and C-Sn bond on enhanced electrochemical properties are further evidenced by density-functional theory(DFT)calculations.Therefore,compared with pristine SnS_(2),SnS_(2)-SPAN cathode displays high specific capacity(218 m Ah g^(-1)at 0.5A g^(-1)over 700 cycles)and ultra-long cycling life(101 m Ah g^(-1)at 5 A g^(-1)up to 28,000 cycles).And a high energy density of 307 Wh kg^(-1)can be realized by the Sn S_(2)-SPAN//Mg pouch cell.Such elaborate and simple design supplies a reference for the exploitation of advanced cathode materials with excellent electrochemical properties for MLHBs.
基金financially supported by the Chongqing Special Key Project of Technology Innovation and Application Development,China(Grant No.cstc2019jscxdxwt BX0016)。
文摘The inherent thermodynamic and kinetic challenges of Mg/Mg H_(2) hydrogen storage materials pose significant obstacles to their development.Alloying has emerged as a highly promising strategy to overcome these challenges.In this study,we synthesized a series of Mg_(93)-Ni_(7-x)-Si_(x)(x=0.4,1.6,5)ternary alloys through microstructure optimization and particle refinement using melting and high energy ball milling techniques.We systematically investigated the effects of varying Ni and Si content on the microstructure and hydrogen storage properties of Mg-Ni-Si alloys.The results demonstrate that variations in Ni and Si content leads to the formation of different types of intermetallic compounds within the alloys,thereby influencing their hydrogen storage properties.Among the tested alloys,Mg_(93)Ni_(2) Si_5 exhibits superior activation and hydrogen absorption properties.The enhanced hydrogenation performance can be attributed to the precipitation of the Mg_(2) Si phase resulting from increased Si content,as well as the refinement of the Mg_(2) Ni_(3) Si phase and the increase in eutectic structure Mg+Mg_(11)Ni_(12)Si_(10).Significantly,the increased intermetallic compounds provide a large number of sites and channels for the nucleation of hydrides as well as the diffusion of hydrogen.During the dehydrogenation process,Ni,serves as the predominant catalytic species,effectively promotes the dissociation of hydrogen and enhances the reaction kinetics.As a result,the hydrogen desorption of the hydrogenated Mg_(93)Ni_(6.6)Si_(0.4)alloy initiates at 180℃,with a reduced activation energy of 105.21 k J/mol.These findings underscore the synergistic and effective roles of Ni and Si elements in enhancing the hydrogen storage properties of Mg-based materials,thus supporting the development of economically viable and promising Mg-based solid-state hydrogen storage materials.
基金The National Natural Science Foundation of China(Grant No.72274052)the National Natural Science Foundation of China(Grant No.72174173).
文摘Frequent flood disasters caused by climate change may lead to tremendous economic and human losses along inland waterways.Emergency response and rescue vessels(ERRVs)play an essential role in minimizing losses and protecting lives and property.However,the path planning of ERRVs has mainly depended on expert experiences instead of rational decision making.This paper proposes an improved artificial potential field(APF)algorithm to optimize the shortest path for ERRVs in the rescue process.To verify the feasibility of the proposed model,eight tests were carried out in two water areas of the Yangtze River.The results showed that the improved APF algorithm was efficient with fewer iterations and that the response time of path planning was reduced to around eight seconds.The improved APF algorithm performed better in the ERRV’s goal achievement,compared with the traditional algorithm.The path planning method for ERRVs proposed in this paper has theoretical and practical value in flood relief.It can be applied in the emergency management of ERRVs to accelerate flood management efficiency and improve capacity to prevent,mitigate,and relieve flood disasters.
基金the National Key R&D Program of China(2016YFB0301100)the National Natural Science Foundation of China(51571043 and 51531002)+1 种基金the Fundamental Research Funds for the Central Universities(2018CDJDCL0019and cqu2018CDHB1A08)Chongqing Technology Innovation and Application Demonstration(Social and Livelihood)Project(cstc2018jscx-msybX0090)
文摘Microstructure, electrical conductivity, and electromagnetic interference(EMI) shielding effectiveness(SE) of cast Mg-x Zn-y Y(x = 2–5, y = 1–10) alloys were systematically investigated to understand the effects of Zn and Y additions on electrical conductivity and electromagnetic shielding effectiveness of the alloys.Experimental results indicate that the electrical conductivity and SE of the Mg-x Zn-y Y alloys decrease with Y/Zn ratio. Electrical conductivity is the main factor that affects the electromagnetic shielding properties and the variation tendency of electromagnetic shielding properties of the Mg-x Zn-y Y alloys is consistent with conductivity. Valence of Y and Zn atoms, configuration of extranuclear electron and volumetric difference are main reasons for the variations in the electrical conductivity. A high density of second phase and the formation of semi-continuous network structure can also improve the SE value at high frequencies.
基金This work was financially supported by the Chongqing Special Key Project of Technology Innovation and Applica-tion Development,China(No.cstc2019jscx-dxwtB0029)the National Natural Science Foundation of China(Nos.51871143 and U2102212)+1 种基金the Science and Technology Committee of Shanghai,China(No.19010500400)the Shanghai Rising-Star Program(No.21QA1403200).
文摘High hydrogen absorption and desorption rates are two significant index parameters for the applications of hydrogen storage tanks.The analysis of the hydrogen absorption and desorption behavior using the isothermal kinetic models is an efficient way to investigate the kinetic mechanism.Multitudinous kinetic models have been developed to describe the kinetic process.However,these kinetic models were de-duced based on some assumptions and only appropriate for specific kinetic measurement methods and rate-controlling steps(RCSs),which sometimes lead to confusion during application.The kinetic analysis procedures using these kinetic models,as well as the key kinetic parameters,are unclear for many researchers who are unfamiliar with this field.These problems will prevent the kinetic models and their analysis methods from revealing the kinetic mechanism of hydrogen storage alloys.Thus,this review mainly focuses on the summarization of kinetic models based on different kinetic measurement methods and RCSs for the chemisorption,surface penetration,diffusion of hydrogen,nucleation and growth,and chemical reaction processes.The analysis procedures of kinetic experimental data are expounded,as well as the effects of temperature,hydrogen pressure,and particle radius.The applications of the kinetic models for different hydrogen storage alloys are also introduced.
基金supported by the National Natural Science Foundation of China(No.52001036)the China Postdoctoral Science Foundation(No.2021M693708)+2 种基金the Chongqing Postdoctoral Scientific Research Foundation(No.cstc2020jcyjbsh X0015)the National Natural Science Foundation of China(51971040,52171101)the Natural Science Foundation of Chongqing(cstc2021jcyj-msxm X0613)。
文摘Magnesium(Mg)and its alloys present great potential to be extensively applied in different applications.However,the relatively poor resistance to corrosion and wear significantly restricts their applications in practice.As one of strategies of surface treatment,micro-arc oxidation(MAO)process attracts a lot of attention,since it does not use neither expensive equipment,nor complicated manipulation.This review systematically discusses MAO mechanism and some typical models,which still need to be further developed to provide a better understanding and guide for future researchers.Subsequently,main influencing factors of MAO process are analyzed in detail.Further,some popular applications of MAO coatings are respectively reviewed,including biomedical application,decoration,thermal control,corrosion and wear resistance,and industrial applications in practice.The existing issues and future perspectives are finally discussed to further accelerate extensive applications of Mg alloys.
基金This work is financially supported by the National Key Research and Development Program of China(Grant No.2016YFB0301100)the Chongqing Foundation and Advanced Research Project(Grant No.cstc2019jcyj-zdxmX0010)+1 种基金the Natural Science Foundation Commission of China(Grant No.51571044 and 51874062)Fundamental Research Funds for the Central Universities(Grant No.2018CDGFCL0005 and 2019CDXYCL0031).
文摘In this work,as-cast Mg-Ni-Y alloys were proposed to develop a feasible material for fracturing balls,and their mechanical performance and corrosion behavior were systematically investigated.Long period stacking order(LPSO)phase was firstly introduced to improve both the mechanical properties and degradation rate of magnesium alloys.With the increase of LPSO phase,the compressive strength was improved significantly,while the elongation of the alloys decreased owing to the relatively brittle nature of LPSO phase.Due to the higher corrosion potential of LPSO phase,the LPSO phase can accelerate the corrosion process by providing more micro-couples.However,the LPSO phase would serve as the corrosion barrier between the corrosion medium and the matrix when the contents of LPSO phase are too high in Mg92.5Ni3Y4.5 and Mg87.5Ni5Y7.5 alloys.As-cast Mg97.5Ni1Y1.5 alloy with satisfactory mechanical properties and rapid degradation rate was successfully developed,exhibiting a high degradation rate of 6675 mm/a(93℃)in 3 wt.%KCl solution and a favorable ultimate compressive strength of 410 MPa.The degradation rate of Mg97.5Ni1Y1.5 alloy is 2-5 times of the current commercial magnesium alloy fracturing materials.
基金financially supported by the National Natural Science Foundation of China (Nos.51971040,52171101)the Natural Science Foundation of Chongqing (No.cstc2021jcyj-msxm X0613)+1 种基金the National Natural Science Foundation of China (Nos.52001036,51971044)the Independent Research Project of State Key Laboratory of Mechanical Transmissions (No.SKLMT-ZZKT-2021M11)。
文摘An efcient and simple in-situ growth strategy has been discovered for the preparation of highly reproducible and continuous symbiotic ZIF-8-based anticorrosion coating by using graphene oxide(GO)/Mg AlNO3layered double hydroxides(G/LDHs) buffer layer as a new type of connecting carrier based on micro-arc oxide(MAO) coating of AZ31 magnesium alloy. The components of ZIF-8 were adsorbed and bounded to the surface of the G/LDHs buffer layer-modified substrates to promote the nucleation of ZIF-8,thus growing a phase-pure, uniform, and good symbiosis ZIF-8 membrane. ZIF-8 particles with different growth times compensate for the grain boundary defects of the G/LDHs coating precursor buffer layer to different degrees. The prepared ZIF-8-based coating has excellent stability and corrosion resistance. The results demonstrate that the G/LDHs buffer layer provides a new channel for the MOF-modified MAO substrate of AZ31 magnesium alloy. It also proves that it is feasible to build high-performance anticorrosive coatings with MOF materials.
基金financially supported by the Chongqing Spe-cial Key Project of Technology Innovation and Application Devel-opment,China(Grant No.cstc2019jscx-dxwtBX0016).
文摘Herein,we report the successful preparation of the FeCoNiCrMn high entropy alloy(HEA)loaded MgH_(2) and HEA’s effect on the hydrogen storage properties of Mg/MgH_(2).The HEA shows high catalytic activity toward hydrogen dissociation and recombination reaction,and successfully suppressed activation energy of dehydrogenation reaction from 151.9 to 90.2 kJ mol-1.Moreover,part of Co and Ni can react with Mg,and produce Mg_(2) Co/Mg_(2) CoH 5 and Mg_(2) Ni/Mg_(2) NiH_(4) during the hydrogen storage processes,further en-hancing dehydrogenation reaction through the“hydrogen pumping”mechanism.Asa result,the MgH_(2)-5 wt%HEA composite can release 5.6 wt%of H_(2) at 280℃ within 10 min,and absorb 5.5 wt%H_(2) within 0.5 min at 150℃.The loaded HEA shows robustness against particle aggregation,leading to stable re-versible hydrogen storage processes at least 50 times.These findings show the synergistic effects of HEA on Mg-based hydrogen storage materials,providing an additional degree of freedom for catalyst design.
基金The authors are grateful for the financial support from the National Key Research and Development Program of China(No.2016YFB0301100)the National Natural Science Foundation of China(Grant Nos.51571044,51671162 and 51874062)the Fundamental Research Funds for the Cen-tral Universities(No.2018CDGFCL0005).
文摘The mechanical properties and bio-corrosion behaviors of as-extruded Mg-4Zn alloys after Sn addition were investigated,systemati-cally.A small amount of Sn addition to Mg-4Zn alloy slightly improved the mechanical properties for solid solution strengthening,and significantly controlled the bio-corrosion rates.Sn participating in the outer layer film formation as SnO/SnO_(2)resisted the bio-corrosion proceeding.Especially,Mg-4Zn-1.5Sn alloy,with a weight loss rate of 0.45 mm/y and hydrogen evolution rate of 0.099 mL/cm^(2)/day,showed cytotoxicity grade of 0 to MC3T3-E1 cells.The perfect alliance of cytocompatibility,suitable mechanical properties and low bio-corrosion rate demonstrates that this Mg-4Zn-1.5Sn alloy is a promising biodegradable magnesium alloy for orthopedic implants.
基金The authors would like to acknowledge the financial supports from the National Natural Science Foundation of China(No.51875062).
文摘The solid–liquid compound casting of Mg-AZ91D and Ti-TC4 alloys was developed by using pure Ni electro-deposited coating.The pouring temperatures of 660℃,690℃,720℃and 750℃were chosen to investigated the effects of casting temperatures on microstructural evolution,properties,and fracture behaviors of Ni-coated TC4/AZ91D bimetals by the solid–liquid compound casting(SLCC).The scanning electron microscopy(SEM)and the energy dispersive spectroscopy(EDS)results showed that the interfacial zone mainly composed of nickel,Mg_(2)Ni and Mg-Al-Ni in the bimetals cast at 660℃.As the pouring temperature was increased to 750℃,the width of the interface zone,which mainly composed ofδ(Mg),Mg_(2)Ni,Mg-Al-Ni,Mg_(3)TiNi_(2) and Al_(3)Ni,gradually increased.The microhardness tests showed that the micro-hardness of the interface zone was smaller than that of TC4 substrate but larger than that of the cast AZ91D matrix.At the pouring temperature of 720℃,the Ni-coated TC4/AZ91D bimetals had the most typical homogeneous interface,which had granular Mg-Al-Ni ternary phase but no ribbon-like Al3Ni binary phase,and achieved the highest shear strength of 97.35MPa.Meanwhile,further fracture behavior analysis showed that most fracture failure of Ni-coated TC4/AZ91D bimetals occurred at the Mg_(2)Ni+δ(Mg)eutectic structure and Al_(3)Ni hard intermetallic.
基金financially National Natural Science Foundation of China(52171100,51971044,U20A20234 and U1910213)the National Key R&D Program of China(2021YFB3701100)the Natural Science Foundation of Chongqing(cstc2019yszx-jcyj X0004)。
文摘The low-density magnesium(Mg)alloys are attractive for the application in aerospace,transportation and other weight-saving-required fields.The mechanical properties and corrosion properties of Mg alloys are the key-property issues for the wide application.It is surprising to find that the solid solution of alloying elements in theα-Mg phase can have multi-effects on the properties of Mg alloys,e.g.,solid solution strengthening,solid solution corrosion-resistance-enhancing,etc.Additionally,the alloy design theory of"solid solution strengthening and ductilizing"proposed by Pan and co-workers has attracted extensive attentions.It is promising that by selected proper multi-alloying-elements(with optimal ratio)solid solutioned in theα-Mg phase,the comprehensive properties of Mg alloys can be synergistically improved.In this work,the solid solution behavior of Mg alloys and the followed solid solution property-enhancing effects were reviewed.The mechanisms proposed recently by researchers for these solid solution property-enhancing behaviors were presented,and the related calculations and predictions were also described.It is shown the demonstrations of the fundamentals for the solid solution property-enhancing of Mg alloys,especially from the atomic inter-reaction aspects,still require elaborated characterization work and calculation work.Additionally,it could be expected that the multi-solute in Mg alloys can bring many possibilities,or,in another saying,"cocktail effects".With understanding the multi-solute interaction behavior and the corresponded solid solution property-enhancing effects,the good balanced high-performance Mg alloys can be developed.
基金financially supported by the National Key R&D Program of China(No.2016YFB0301100)the National Natural Science Foundation of China(Nos.51571043 and 51531002)the Fundamental Research Funds for the Central Universities(Nos.2018CDJDCL0019 and cqu2018CDHB1A08)
文摘The influence of Zn on the strain hardening of as-extruded Mg-x Zn(x = 1, 2, 3 and 4 wt%) magnesium alloys was investigated using uniaxial tensile tests at 10^(-3)s^(-1) at room temperature. The strain hardening rate,the strain hardening exponent and the hardening capacity were obtained from true plastic stress-strain curves. There were almost no second phases in the as-extruded Mg-Zn magnesium alloys. Average grain sizes of the four as-extruded alloys were about 17.8 μm. With increasing Zn content from 1 to 4 wt%, the strain hardening rate increased from 2850 MPa to 6810 MPa at(б-б_(0.2)) = 60 MPa, the strain hardening exponent n increased from 0.160 to 0.203, and the hardening capacity, Hc increased from 1.17 to 2.34.The difference in strain hardening response of these Mg-Zn alloys might be mainly caused by weaker basal texture and more solute atoms in the α-Mg matrix with higher Zn content.
