Seawater splitting provides a sustainable approach for large-scale hydrogen production without straining freshwater resources.However,the challenge lies in achieving high catalytic activity and stability due to electr...Seawater splitting provides a sustainable approach for large-scale hydrogen production without straining freshwater resources.However,the challenge lies in achieving high catalytic activity and stability due to electrocatalyst deactivation from structural degradation,poor corrosion resistance,and surface instability in both alkaline and seawater electrolysis.To address this,we propose a novel strategy combining Fe-doping with dual-phase lattice strain engineering in nickel-molybdenum transition metal nitrides(TMNs).The Fe-doped Ni_(3)Mo_(3)N/Mo_(2)N electrocatalyst exhibits compressive lattice strains of-4.52%and-2.91%in the Ni_(3)Mo_(3)N and Mo_(2)N phases,respectively,enhancing its structural integrity and electronic properties.Consequently,Fe-Ni_(3)Mo_(3)N/Mo_(2)N achieves low overpotentials of 167 and 371 mV at current densities of 10 and 500 mA cm^(-2),respectively,in 1 M alkaline seawater,with exceptional stability over 100 h at 100 and 500 mA cm^(-2).Theoretical calculations reveal that these compressive strains optimize the adsorption of OER intermediates and improve catalytic kinetics.This work demonstrates the promise of dual-phase lattice strain engineering in TMNs for efficient,durable,and scalable electrocatalysts in seawater electrolysis,a strategy that has yet to be fully explored for OER.展开更多
Continuous annealing simulation is used in studying the influence of continuous annealing process parameters on the microstructure and mechanical properties of a GPa-grade C-Si-Mn-Cr-Mo dual-phase steel.The experiment...Continuous annealing simulation is used in studying the influence of continuous annealing process parameters on the microstructure and mechanical properties of a GPa-grade C-Si-Mn-Cr-Mo dual-phase steel.The experimental results indicate that increasing soaking time increases the volume fraction of martensite and the size of martensite islands, as well as tensile strength(TS) and yield strength(YS),while decreasing plasticity.As the steel slowly cools to a lower temperature prior to final quenching, TS and YS decrease, whereas elongation increases.The decrease in martensite content is due to the partial decomposition of austenite into ferrite during long slow cooling before quenching.As overaging temperature increases because of the tempering of martensite and aging of ferrite, TS decreases and YS increases.Work hardening analysis shows that in the initial stage of deformation, low overaging temperatures enhance work hardening ability.展开更多
With the upgrade of armor protection materials,higher requirements are put forward for the penetration performance of tungsten alloy kinetic energy armor-piercing projectiles,and the penetration performance is closely...With the upgrade of armor protection materials,higher requirements are put forward for the penetration performance of tungsten alloy kinetic energy armor-piercing projectiles,and the penetration performance is closely related to the adiabatic shear band under extreme stress conditions.Here,the detailed analysis of the adiabatic shear band microstructure evolution of a dual-phase 90W-Ni-Fe alloy under a high strain rate was conducted by combining advanced electron microscopic characterization,while discussing shear fracture from a mechanical perspective under thermoplastic instability.The high temperature and high stress environment inside the adiabatic shear band led to the refinement of the W phase andγ-(Ni,Fe)phase grains to the submicron level,and induced the elements redistribution of W,Ni,and Fe to precipitate W nanocrystalline with hardness as high as 11.7 GPa along the recrystallization grain boundaries of theγ-(Ni,Fe)phase.Mechanical incompatibility caused by the hardness difference between W nanocrystalline andγ-(Ni,Fe)phases led to a strain gradient at the interface.The microvoids preferentially nucleated at the W nanocrystalline/γ-(Ni,Fe)phase interface,then merged to form microcracks and grew further,leading to shear failure.展开更多
Developing efficient and durable non-noble-metal catalysts for the oxygen evolution reaction(OER)in acidic media remains a critical challenge for proton-exchange membrane water electrolysis.Here,we report a dual-phase...Developing efficient and durable non-noble-metal catalysts for the oxygen evolution reaction(OER)in acidic media remains a critical challenge for proton-exchange membrane water electrolysis.Here,we report a dual-phase Mn_(3)O_(4)-Co_(2)MnO_(4)hybrid oxide electrocatalyst synthesized via a sulfur-assisted coelectrodeposition strategy in a choline chloride/ethylene glycol-based deep eutectic solvent,followed by annealing.The incorporation of sulfur facilitates the formation of a cubic spinel Co_(2)MnO_(4)phase within the Mn_(3)O_(4)host,optimizing electronic conductivity and stabilizing the catalytic layer by strengthening Mn-O bonds.When supported on a corrosion-resistant Pt/Ti substrate,the composite electrode achieves a low overpotential of 317 mV at 10 mA cm^(-2)and sustains stable operation for over 100 h in 0.05 M H_(2)SO_(4)(pH=1),outperforming most MnO_(x)-based catalysts and approaching noble-metal benchmarks.Density functional theory calculations reveal that the Co_(2)MnO_(4)phase lowers the energy barrier for the rate-determining OOH^(*)→O_(2)step,while in-situ spectroscopic analyses confirm its structural integrity under acidic OER conditions.Furthermore,electrolyte dissociation kinetics significantly influences performance,with HClO_(4) exhibiting superior mass transfer due to its high proton conductivity.This work provides a rational design pathway for non-noble-metal acidic OER catalysts through phase engineering and electrolyte optimization,advancing sustainable hydrogen production technologies.展开更多
Transition metal sulfides and oxides with suitable dielectric features have been considered as significant candidates for advanced electromagnetic wave(EMW)absorption systems.However,there is still an urgent need to r...Transition metal sulfides and oxides with suitable dielectric features have been considered as significant candidates for advanced electromagnetic wave(EMW)absorption systems.However,there is still an urgent need to realize controllable regulation of their interfacial polarization behavior.Herein,we prepared dual-phase CoFe_(2)S_(4)/CoFe_(2)O_(4)composites with an average size of~1.43μm through a hydrothermal method.The unique nanoflower morphology promoted the multiple reflection and scattering of the incident EMW,contributing to the improvement of the loss ability.By varying the temperature during the solvothermal reaction,a facile adjustment of the CoFe_(2)O_(4)to CoFe_(2)S_(4)ratio can be realized.The difference in electronegativity and band gap facilitated the directional electron transfer from CoFe_(2)O_(4)side to CoFe_(2)S_(4)side at the dual-phase heterogenous interfaces,leading to spatial charge redistribution and optimized in-plane interfacial polarization.Moreover,the different distribution of CoFe_(2)O_(4)and CoFe_(2)S_(4)phases on different nanosheets exaggerated the deviation of interlayer positive/negative charges from the original equilibrium centers,thereby contributing to the enhancement of interlayer polarization.As a result,CoFe_(2)S_(4)/CoFe_(2)O_(4)with higher dual-phase density exhibited strongest absorption intensity of-77.2 dB with an effective absorption bandwidth of 7.2 GHz at 1.8 mm.This work demonstrates the effective EMW attenuation optimization in transition metal sulfides and oxides and paves the way for modulating multiple interfacial polarization responses in inhomogeneous absorber systems.展开更多
Different stress states have a significant influence on the magnitude of the microscopic plastic strain and result in the development of the microstructure evolution.As a result,a comprehensive understanding of the di...Different stress states have a significant influence on the magnitude of the microscopic plastic strain and result in the development of the microstructure evolution.As a result,a comprehensive understanding of the different scale variation on microstructure evolution during bending deformation is essential.The advanced high strength dual-phase(DP1180)steel was investigated using multiscale microstructure-based 3D representative volume element(RVE)modelling technology with emphasis on understanding the relationship between the microstructure,localised stress-strain evolution as well as the deformation characteristics in the bending process.It is demonstrated that the localised development in bending can be more accurately described by microscopic deformation when taking into account microstructural properties.Microstructure-based 3D RVEs from each chosen bending condition generally have comparable localisation properties,whilst the magnitudes and intensities differ.In addition,the most severe localised bands are predicted to occur close to the ferrite and martensite phase boundaries where the martensite grains are close together or have a somewhat sharp edge.The numerically predicted results for the microstructure evolution,shear bands development and stress and strain distribution after 3-point bending exhibit a good agreement with the relevant experimental observations.展开更多
A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepa...A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepared by common gas atomization and dual-phase flow atomization under similar conditions were compared. The experimental results show that the dual-phase flow-atomized powders have average particle sizes that are one-half that of the common gas-atomized particles;additionally, they possess a finer microstructure and higher cooling rate under the same atomization gas pressure and the same gas flow. The Weber number in the crash criteria of liquid atomization is adopted to measure the crash ability of the atomization media. The Weber number of the dual-phase flow atomization medium is the sum of that of the gas and the solid particles. Furthermore, the critical equation of the crash model in dual-phase flow atomization is established, and the main regularities associated with this process were analyzed.展开更多
The conventional melting methods were used to obtain in situ TiC particle-reinforced dual-phase steel,followed by hot rolling and heat treatment processes.The aim was to investigate the effect of TiC particles on the ...The conventional melting methods were used to obtain in situ TiC particle-reinforced dual-phase steel,followed by hot rolling and heat treatment processes.The aim was to investigate the effect of TiC particles on the fracture behavior of dual-phase steel at different annealing temperatures,by analyzing the microstructure and tensile behavior of the multiscale TiC particle-reinforced dual-phase steel.The results showed that TiC particles precipitated in the as-cast microstructure of dual-phase steel were distributed along the grain boundaries.During hot rolling,the grain boundary-like morphology of the micron-sized TiC particles was disrupted,and the particles became more refined and evenly distributed in the matrix.The tensile tests revealed that the strength of the TiC particle-reinforced dual-phase steel increased with increasing martensite content,while the elongation decreased.These results were similar to those of conventional steel.The addition of 1 vol.%multiscale TiC particles improved the strength of the dual-phase steel but did not affect elongation of the steel.Cracks and holes were primarily concentrated around the TiC particles rather than at the interface of martensite and ferrite.The main causes of crack sprouting were TiC particle interface cracking and TiC particle internal fragmentation.Overall,the study demonstrated the potential of multiscale TiC particle-reinforced dual-phase steel as a strong and tough material.The refined distribution of TiC particles in the matrix improved the strength of the material without compromising its elongation.The results also highlighted the importance of careful selection of reinforcement particles to avoid detrimental effects on the fracture behavior of the material.展开更多
According to the stress-strain curves of single-phase martensite and single-phase ferrite steels,whose compositions are similar to those of martensite and ferrite in low Si-Mn-Nb dual-phase steel,the stress-strain cur...According to the stress-strain curves of single-phase martensite and single-phase ferrite steels,whose compositions are similar to those of martensite and ferrite in low Si-Mn-Nb dual-phase steel,the stress-strain curve of the low Si-Mn-Nb dual-phase steel was simulated using the finite element method（FEM）.The simulated result was compared with the measured one and they fit closely with each other, which proves that the FE model is correct.Based on the FE model,the microstress and microstrain of the dual-phase steel were analyzed. Meanwhile,the effective factors such as the volume fraction of martensite and the yield stress ratio between martensite and ferrite phases on the stress-strain curves of the dual-phase steel were simulated,too.The simulated results indicate that for the low Si-Mn-Nb dual-phase steel, the maximum stress occurs in the martensite region,while the maximum strain occurs in the ferrite one.The effect of the volume fraction of martensite（fm） and the yield stress ratio on the stress-strain curve of the dual-phase steel is small in the elastic part,while it is obvious in the plastic part.In the plastic part of this curve,the strain decreases with the increase of f_M,while it decreases with the decrease of the yield stress ratio.展开更多
The microstructures and mechanical properties of C-Mn-Cr-Nb and C-Mn-Si-Nb ultra-high strength dual-phase steels were studied by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and tens...The microstructures and mechanical properties of C-Mn-Cr-Nb and C-Mn-Si-Nb ultra-high strength dual-phase steels were studied by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and tensile test. The results show that Si can promote the transformation of austenite （γ） to ferrite （α）, enlarge the （α＋γ） region, and increase the aging stability of martensite by inhibiting carbide precipitation. Adding Cr leads to the formation of retained austenite and martensite/austenite （M/A） constituents, as well as the decomposi- tion of martensite during the overaging stage. Both of the steels show higher initial strain-hardening rates and two-stage strain-hardening characteristics. The C-Mn-Si-Nb steel shows the higher strain-hardening rate than the C-Mn-Cr-Nb steel in the first stage; however, there is no significant difference in the second stage. Although the tensile strength and elongation of the two steels both exceed 1000 MPa and 15%, respectively, the comprehensive mechanical properties of the C-Mn-Si-Nb steel are superior.展开更多
A C–Mn dual-phase steel was soaked at 800°C for 90 s and then either rapidly cooled to 450°C and held for 30 s(process A) or rapidly cooled to 350°C and then reheated to 450°C(process B) to simula...A C–Mn dual-phase steel was soaked at 800°C for 90 s and then either rapidly cooled to 450°C and held for 30 s(process A) or rapidly cooled to 350°C and then reheated to 450°C(process B) to simulate the hot-dip galvanizing process. The influence of the hot-dip galvanizing process on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel(DP600) was investigated using optical microscopy, scanning electron microscopy(SEM), transmission electron microscopy(TEM), and tensile tests. The results showed that, in the case of process A, the microstructure of DP600 was composed of ferrite, martensite, and a small amount of bainite. The granular bainite was formed in the hot-dip galvanizing stage, and martensite islands were formed in the final cooling stage after hot-dip galvanizing. By contrast, in the case of process B, the microstructure of the DP600 was composed of ferrite, martensite, bainite, and cementite. In addition, compared with the yield strength(YS) of the DP600 annealed by process A, that for the DP600 annealed by process B increased by approximately 50 MPa because of the tempering of the martensite formed during rapid cooling. The work-hardening coefficient(n value) of the DP600 steel annealed by process B clearly decreased because the increase of the YS affected the computation result for the n value. However, the ultimate tensile strength(UTS) and elongation(A80) of the DP600 annealed by process B exhibited less variation compared with those of the DP600 annealed by process A. Therefore, DP600 with excellent comprehensive mechanical properties(YS = 362 MPa, UTS = 638 MPa, A_(80) = 24.3%, n = 0.17) was obtained via process A.展开更多
Dual-phase Mg-Li alloys sheets were rolled at four different temperatures ranging from liquid nitrogen to 300℃to explore effect of rolling temperature on texture and mechanical properties of the material.Crystal plas...Dual-phase Mg-Li alloys sheets were rolled at four different temperatures ranging from liquid nitrogen to 300℃to explore effect of rolling temperature on texture and mechanical properties of the material.Crystal plasticity simulation was utilized to illustrate the influence of slip activity on rolling texture development.The results show that the rolling texture is largely depended on deformation temperature.Unlike commercial Mg alloys,the critical resolved shear stress of basal slip inα-Mg phase of Mg-Li alloy decreased more significantly by increasing temperature compared to that of pyramidal<c+a>slip.Enhancement of basal slip by increasing temperature triggered a decrease of split angle of basal poles for the double-peak texture.Prismaticslip largely enhanced by increasing temperature upon 200℃,which induced a wider orientation spread along the transverse direction.For theβ-Li phase,the promotion of{110}<111>slip system at elevated temperature triggered the enhancement of{211}<110>and{111}<211>texture components.The cryo-rolled sample exhibited the highest strength compared to the others due to a strong hardening behavior at this temperature.A two-stage hardening behavior was observed in these as-rolled dual-phase alloys.Strain transition at phase boundaries could be the reason for appearance of this two-stage hardening.展开更多
Low-carbon Cr-Mo micro-alloyed deep drawing dual-phase steels were designed in laboratory. As the mi- crostructure and texture evolution in hot-rolled strips and annealed sheets were investigated using SEM, TEM and XR...Low-carbon Cr-Mo micro-alloyed deep drawing dual-phase steels were designed in laboratory. As the mi- crostructure and texture evolution in hot-rolled strips and annealed sheets were investigated using SEM, TEM and XRD technologies, the attribution of solute Mo and MoC particles to DP sheets＇ drawing capacity was investigated. The precipitation thermodynamics were also calculated by Thermo-calc software. Results show that the precipitates in hot-rolled strips mainly are MoC, AIN and MnS, and with the increase of Mo addition, finer and denser MoC par- ticles precipitated in matrix and along grain boundaries of ferrite more easily. Weak textures are shown in the hot- rolled strips, and {112}~110~ and {223}%110~ components tend to be stable in subsequent cold rolling process. During annealing, on one hand, the development of ~lll~//ND texture is suppressed because finer MoC particles prevent the grain boundary migration. On the other hand, unfavorable texture {001 } %110：〉 significantly reduces with Mo increasing, which is attributed to that part of solution C in matrix has been fixed during recrystallization. In addition, the addition of Mo can enhance hardenability strongly and MoC easily re-dissolve at high temperature, which is favor to form martensite in dual-phase steel.展开更多
A series of oxygen permeable dual-phase composite oxides 60 wt% Ce0.8Gd0.2O2-δ-40 wt% LnBaCo2O5＋δ （CGO-LBCO, Ln = La, Pr, Nd, Sin, Gd and Y） were synthesized through a sol-gel route and effects of the Ln3＋ catio...A series of oxygen permeable dual-phase composite oxides 60 wt% Ce0.8Gd0.2O2-δ-40 wt% LnBaCo2O5＋δ （CGO-LBCO, Ln = La, Pr, Nd, Sin, Gd and Y） were synthesized through a sol-gel route and effects of the Ln3＋ cations on their phase structure, oxygen permeability and chemical stability against CO2 were investigated systemically by XRD, SEM, TG-DSC and oxygen permeation experiments. XRD patterns reveal that the larger Ln3＋ cations （La3＋, Pr3＋ and Nd3＋） successfully stabilized the double-layered perovskite structure of sintered LBCO, while the smaller ones （Sm3＋, Gd3＋, and Y3＋） resulted in the partial decomposition of LBCO with some impurities formed. CGO-PBCO yields the highest oxygen permeation flux, reaching 2.8× 10^-7 mol.s-1.cm-2 at 925 ℃ with 1 mm thickness under air/He gradient. The TG-DSC profiles in 20 mol% CO2/N2 and oxygen permeability experiments with CO2 as sweep gas show that CGO-YBCO demonstrates the best chemical stability against CO2, possibly due to its minimum basicity. The stable oxygen permeation flux of CGO-YBCO under CO2 atmosphere reveals its potential application in the oxy-fuel combustion route for CO2 capture.展开更多
Hardness tests and transmission electron microscopy were used to investigate the strategy of tailoring the phase fraction of precipitates in an Al-Zn-Mg-Cu alloy strengthened by T’ and η’ phases. Different phase fr...Hardness tests and transmission electron microscopy were used to investigate the strategy of tailoring the phase fraction of precipitates in an Al-Zn-Mg-Cu alloy strengthened by T’ and η’ phases. Different phase fractions of T’ and η’ phases are presented in samples subjected to either single or two stages of ageing treatments at 120 and 150 ℃.For both types of ageing, the precipitation of η’ phase is found to be promoted by ageing at lower temperature and its phase fraction increases with prolonging ageing time at 120 ℃;whereas the phase fractions of T’ and η’ phases almost remain constant during ageing at 150 ℃. Besides, the strain fields produced by T’ and η’ phases were analyzed by using the geometric phase analysis technique, and on a macroscale the contributions of T’ and η’ phases to precipitation strengthening have been quantitatively predicted by combining the size, phase fraction and number density of precipitates.展开更多
Continuous annealing simulation tests were conducted by using a continuous annealing thermomechanical simulator. Holding times of 5, 60, 180, and 480 seconds for an intercritical annealing temperature of 820℃ were ad...Continuous annealing simulation tests were conducted by using a continuous annealing thermomechanical simulator. Holding times of 5, 60, 180, and 480 seconds for an intercritical annealing temperature of 820℃ were adopted to investigate the evolution of the mierostructure and mechanical properties of ferrite-bainite dual-phase steel. The ferrite-bainite dual-phase steel was characterized by high strength and low yield ratio due to the presence of the constituents （polygonal ferrite, bainite, martensite and retained austenite） of the steel microstructure. Specimen 3 exhibits the highest value of A50 （7.67%） and a product of Rm × A50 （10453MPa%） after a 180s holding. This is likely attributed to the presence of a C-enriched retained anstenite in the microstructure. And the effect of martensite islands and carbide precipitate is thought to be able to contribute in strengthening the present steel. It is expected that equilibrium of anstenite fraction would be reached for reasonable intercritical holding period, regardless of the heating temperature. The results suggest that long increasing holding times may not be needed because the major phase of the microstructure does not change very significantly. It is favorable for industrial production of DP steels to shorten holding times. Key words： ferrite-bainite dual-phase steel; holding time; martensite islands; mechanical properties展开更多
In a typical process, C-Mn steel was annealed at 800℃ for 180 s, and then cooled rapidly to obtain the ferrite-martensite microstructure. After pre-straining, the specimens were baked and the corresponding bake-harde...In a typical process, C-Mn steel was annealed at 800℃ for 180 s, and then cooled rapidly to obtain the ferrite-martensite microstructure. After pre-straining, the specimens were baked and the corresponding bake-hardening （BH） values were determined as a function of pre-strain, baking temperature, and baking time. The influences ofpre-strain, baking temperature and baking time on the microstructure evolution and bake-hardening behavior of the dual-phase steel were investigated systematically. It was found that the BH value apparently increased with an increase in pre-strain in the range from 0 to 1%; however, increasing pre-strain from 1% to 8% led to a decrease in the BH value. Furthermore, an increase in baking temperature favored a gradual improvement in the BH value because of the formation of Cottrell atmosphere and the precipitation of carbides in both the ferrite and martensite phases. The BH value reached a maximum of 110 MPa at a baking temperature of 300℃. Moreover, the BH value enhanced significantly with increasing baking time from 10 to 100 min.展开更多
The evolution of the microstructure and tensile properties of dual-phase Al0.6CoCrFeNi high-entropy alloys(HEAs)subjected to cold rolling was investigated.The homogenized Al0.6CoCrFeNi alloys consisted of face-centere...The evolution of the microstructure and tensile properties of dual-phase Al0.6CoCrFeNi high-entropy alloys(HEAs)subjected to cold rolling was investigated.The homogenized Al0.6CoCrFeNi alloys consisted of face-centered-cubic and body-centered-cubic phases,presenting similar mechanical behavior as the as-cast state.The yield and tensile strengths of the alloys could be dramatically enhanced to^1205 MPa and^1318 MPa after 50%rolling reduction,respectively.A power-law relationship was discovered between the strain-hardening exponent and rolling reduction.The tensile strengths of this dual-phase HEA with different cold rolling treatments were predicted,mainly based on the Hollomon relationship,by the strain-hardening exponent,and showed good agreement with the experimental results.展开更多
The dynamic tensile behavior and deformation mechanism of ultra-high-strength dual-phase(UHS-DP1000)steel were investigated over a wide range of strain rates from 10^-4 to 10^3 s^-1.As the strain rate increases,the tr...The dynamic tensile behavior and deformation mechanism of ultra-high-strength dual-phase(UHS-DP1000)steel were investigated over a wide range of strain rates from 10^-4 to 10^3 s^-1.As the strain rate increases,the transition strain decreases from 2.73 to 1.92,and the martensite plastic deformation starts earlier.At strain rate of 10^-4-0.5 s^-l,the inhomogeneous plastic deformation ability increases because the dislocation density in the ferrite matrix increases.This leads to a decrease in uni form elongation and an increase in fracture elongation.When the strain rate increases from 0.5 to 500s^-l.the amount of mobile dislocation increases,which is the main reason for the enhancing uniform elongation and fracture elongation.Mea nwhile,because the dislocation motio n resistance rapidly in creases,the yield strength and ultimate tensile strength also increase.When the strain rate is higher than 500 s^-1.the hardening behavior caused by the dislocation motion resistance has not been offset by softening due to the mobile dislocation and adiabatic heating.The voids at the early stage of deformation could not uniformly form and grow,and thus the homogeneous plastic deformation ability decreases.展开更多
In this study,a novel strategy for developingα+βdual-phase titanium alloys with low Young's modulus and high yield strength was proposed,and a Ti-15Nb-5Zr-4Sn-1 Fe alloy was developed through theoretical composi...In this study,a novel strategy for developingα+βdual-phase titanium alloys with low Young's modulus and high yield strength was proposed,and a Ti-15Nb-5Zr-4Sn-1 Fe alloy was developed through theoretical composition design and microstructure manipulation.After hot-rolling and subsequent annealing,a high volume fraction of ultrafine grainedαphase embedded in metastableβ-matrix was formed in the microstructure as intended.Consequently,this alloy exhibits both low Young's modulus(61 GPa)and high yield strength(912 MPa).The experimental results prove that the proposed strategy is appropriate for developing titanium alloys with superior yield strength-to-modulus ratio than those of conventional metallic biomedical materials.Present study might shed light on the research and development of advanced biomedical titanium alloys with low Young's modulus and high yield strength.展开更多
基金supported by the Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy(2020CB1007)Guangxi Key Laboratory of Information Materials(Guangxi Science and Technology Program AD25069070)+1 种基金Nationally Funded Postdoctoral Researcher Program(GZC20230756)China Postdoctoral Science Foundation(2024M750858)。
文摘Seawater splitting provides a sustainable approach for large-scale hydrogen production without straining freshwater resources.However,the challenge lies in achieving high catalytic activity and stability due to electrocatalyst deactivation from structural degradation,poor corrosion resistance,and surface instability in both alkaline and seawater electrolysis.To address this,we propose a novel strategy combining Fe-doping with dual-phase lattice strain engineering in nickel-molybdenum transition metal nitrides(TMNs).The Fe-doped Ni_(3)Mo_(3)N/Mo_(2)N electrocatalyst exhibits compressive lattice strains of-4.52%and-2.91%in the Ni_(3)Mo_(3)N and Mo_(2)N phases,respectively,enhancing its structural integrity and electronic properties.Consequently,Fe-Ni_(3)Mo_(3)N/Mo_(2)N achieves low overpotentials of 167 and 371 mV at current densities of 10 and 500 mA cm^(-2),respectively,in 1 M alkaline seawater,with exceptional stability over 100 h at 100 and 500 mA cm^(-2).Theoretical calculations reveal that these compressive strains optimize the adsorption of OER intermediates and improve catalytic kinetics.This work demonstrates the promise of dual-phase lattice strain engineering in TMNs for efficient,durable,and scalable electrocatalysts in seawater electrolysis,a strategy that has yet to be fully explored for OER.
文摘Continuous annealing simulation is used in studying the influence of continuous annealing process parameters on the microstructure and mechanical properties of a GPa-grade C-Si-Mn-Cr-Mo dual-phase steel.The experimental results indicate that increasing soaking time increases the volume fraction of martensite and the size of martensite islands, as well as tensile strength(TS) and yield strength(YS),while decreasing plasticity.As the steel slowly cools to a lower temperature prior to final quenching, TS and YS decrease, whereas elongation increases.The decrease in martensite content is due to the partial decomposition of austenite into ferrite during long slow cooling before quenching.As overaging temperature increases because of the tempering of martensite and aging of ferrite, TS decreases and YS increases.Work hardening analysis shows that in the initial stage of deformation, low overaging temperatures enhance work hardening ability.
基金supported by the National Natural Science Foundation of China(No.51931012)the Science and Technology Innovation Program of Hunan Province(No.2023RC3068).
文摘With the upgrade of armor protection materials,higher requirements are put forward for the penetration performance of tungsten alloy kinetic energy armor-piercing projectiles,and the penetration performance is closely related to the adiabatic shear band under extreme stress conditions.Here,the detailed analysis of the adiabatic shear band microstructure evolution of a dual-phase 90W-Ni-Fe alloy under a high strain rate was conducted by combining advanced electron microscopic characterization,while discussing shear fracture from a mechanical perspective under thermoplastic instability.The high temperature and high stress environment inside the adiabatic shear band led to the refinement of the W phase andγ-(Ni,Fe)phase grains to the submicron level,and induced the elements redistribution of W,Ni,and Fe to precipitate W nanocrystalline with hardness as high as 11.7 GPa along the recrystallization grain boundaries of theγ-(Ni,Fe)phase.Mechanical incompatibility caused by the hardness difference between W nanocrystalline andγ-(Ni,Fe)phases led to a strain gradient at the interface.The microvoids preferentially nucleated at the W nanocrystalline/γ-(Ni,Fe)phase interface,then merged to form microcracks and grew further,leading to shear failure.
基金financial support of the National Natural Science Foundation of China(52361039,21962008)Yunnan Ten Thousand Talents Plan Young&Elite Talents Project(YNWR-QN BJ-2018-346)。
文摘Developing efficient and durable non-noble-metal catalysts for the oxygen evolution reaction(OER)in acidic media remains a critical challenge for proton-exchange membrane water electrolysis.Here,we report a dual-phase Mn_(3)O_(4)-Co_(2)MnO_(4)hybrid oxide electrocatalyst synthesized via a sulfur-assisted coelectrodeposition strategy in a choline chloride/ethylene glycol-based deep eutectic solvent,followed by annealing.The incorporation of sulfur facilitates the formation of a cubic spinel Co_(2)MnO_(4)phase within the Mn_(3)O_(4)host,optimizing electronic conductivity and stabilizing the catalytic layer by strengthening Mn-O bonds.When supported on a corrosion-resistant Pt/Ti substrate,the composite electrode achieves a low overpotential of 317 mV at 10 mA cm^(-2)and sustains stable operation for over 100 h in 0.05 M H_(2)SO_(4)(pH=1),outperforming most MnO_(x)-based catalysts and approaching noble-metal benchmarks.Density functional theory calculations reveal that the Co_(2)MnO_(4)phase lowers the energy barrier for the rate-determining OOH^(*)→O_(2)step,while in-situ spectroscopic analyses confirm its structural integrity under acidic OER conditions.Furthermore,electrolyte dissociation kinetics significantly influences performance,with HClO_(4) exhibiting superior mass transfer due to its high proton conductivity.This work provides a rational design pathway for non-noble-metal acidic OER catalysts through phase engineering and electrolyte optimization,advancing sustainable hydrogen production technologies.
基金financially supported by Ningbo Yongjiang Talent Program(No.2024A-421-G)Ningbo Key Research and Development Program(No.2024Z210)+1 种基金Ningbo Key Laboratory of Molecular Target Screening and Application(No.2023-BZDS)Ningbo Top Medical and Health Research Program(No.2023030514)
文摘Transition metal sulfides and oxides with suitable dielectric features have been considered as significant candidates for advanced electromagnetic wave(EMW)absorption systems.However,there is still an urgent need to realize controllable regulation of their interfacial polarization behavior.Herein,we prepared dual-phase CoFe_(2)S_(4)/CoFe_(2)O_(4)composites with an average size of~1.43μm through a hydrothermal method.The unique nanoflower morphology promoted the multiple reflection and scattering of the incident EMW,contributing to the improvement of the loss ability.By varying the temperature during the solvothermal reaction,a facile adjustment of the CoFe_(2)O_(4)to CoFe_(2)S_(4)ratio can be realized.The difference in electronegativity and band gap facilitated the directional electron transfer from CoFe_(2)O_(4)side to CoFe_(2)S_(4)side at the dual-phase heterogenous interfaces,leading to spatial charge redistribution and optimized in-plane interfacial polarization.Moreover,the different distribution of CoFe_(2)O_(4)and CoFe_(2)S_(4)phases on different nanosheets exaggerated the deviation of interlayer positive/negative charges from the original equilibrium centers,thereby contributing to the enhancement of interlayer polarization.As a result,CoFe_(2)S_(4)/CoFe_(2)O_(4)with higher dual-phase density exhibited strongest absorption intensity of-77.2 dB with an effective absorption bandwidth of 7.2 GHz at 1.8 mm.This work demonstrates the effective EMW attenuation optimization in transition metal sulfides and oxides and paves the way for modulating multiple interfacial polarization responses in inhomogeneous absorber systems.
基金supported by HBIS Group under the Grant No.IRIS 200506003.
文摘Different stress states have a significant influence on the magnitude of the microscopic plastic strain and result in the development of the microstructure evolution.As a result,a comprehensive understanding of the different scale variation on microstructure evolution during bending deformation is essential.The advanced high strength dual-phase(DP1180)steel was investigated using multiscale microstructure-based 3D representative volume element(RVE)modelling technology with emphasis on understanding the relationship between the microstructure,localised stress-strain evolution as well as the deformation characteristics in the bending process.It is demonstrated that the localised development in bending can be more accurately described by microscopic deformation when taking into account microstructural properties.Microstructure-based 3D RVEs from each chosen bending condition generally have comparable localisation properties,whilst the magnitudes and intensities differ.In addition,the most severe localised bands are predicted to occur close to the ferrite and martensite phase boundaries where the martensite grains are close together or have a somewhat sharp edge.The numerically predicted results for the microstructure evolution,shear bands development and stress and strain distribution after 3-point bending exhibit a good agreement with the relevant experimental observations.
文摘A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepared by common gas atomization and dual-phase flow atomization under similar conditions were compared. The experimental results show that the dual-phase flow-atomized powders have average particle sizes that are one-half that of the common gas-atomized particles;additionally, they possess a finer microstructure and higher cooling rate under the same atomization gas pressure and the same gas flow. The Weber number in the crash criteria of liquid atomization is adopted to measure the crash ability of the atomization media. The Weber number of the dual-phase flow atomization medium is the sum of that of the gas and the solid particles. Furthermore, the critical equation of the crash model in dual-phase flow atomization is established, and the main regularities associated with this process were analyzed.
基金the National Basic Research Program,China(No.2022YFB3705300)National Natural Science Foundation of China(Nos.52274380,51874089,and U1960112)LiaoNing Revitalization Talents Program(XLYC2007030).
文摘The conventional melting methods were used to obtain in situ TiC particle-reinforced dual-phase steel,followed by hot rolling and heat treatment processes.The aim was to investigate the effect of TiC particles on the fracture behavior of dual-phase steel at different annealing temperatures,by analyzing the microstructure and tensile behavior of the multiscale TiC particle-reinforced dual-phase steel.The results showed that TiC particles precipitated in the as-cast microstructure of dual-phase steel were distributed along the grain boundaries.During hot rolling,the grain boundary-like morphology of the micron-sized TiC particles was disrupted,and the particles became more refined and evenly distributed in the matrix.The tensile tests revealed that the strength of the TiC particle-reinforced dual-phase steel increased with increasing martensite content,while the elongation decreased.These results were similar to those of conventional steel.The addition of 1 vol.%multiscale TiC particles improved the strength of the dual-phase steel but did not affect elongation of the steel.Cracks and holes were primarily concentrated around the TiC particles rather than at the interface of martensite and ferrite.The main causes of crack sprouting were TiC particle interface cracking and TiC particle internal fragmentation.Overall,the study demonstrated the potential of multiscale TiC particle-reinforced dual-phase steel as a strong and tough material.The refined distribution of TiC particles in the matrix improved the strength of the material without compromising its elongation.The results also highlighted the importance of careful selection of reinforcement particles to avoid detrimental effects on the fracture behavior of the material.
基金supported by the Natural Science Foundation of Hebei Province(No.E2008000822) the Program for One Hundred Excellent Talents of Hebei Province,China.
文摘According to the stress-strain curves of single-phase martensite and single-phase ferrite steels,whose compositions are similar to those of martensite and ferrite in low Si-Mn-Nb dual-phase steel,the stress-strain curve of the low Si-Mn-Nb dual-phase steel was simulated using the finite element method（FEM）.The simulated result was compared with the measured one and they fit closely with each other, which proves that the FE model is correct.Based on the FE model,the microstress and microstrain of the dual-phase steel were analyzed. Meanwhile,the effective factors such as the volume fraction of martensite and the yield stress ratio between martensite and ferrite phases on the stress-strain curves of the dual-phase steel were simulated,too.The simulated results indicate that for the low Si-Mn-Nb dual-phase steel, the maximum stress occurs in the martensite region,while the maximum strain occurs in the ferrite one.The effect of the volume fraction of martensite（fm） and the yield stress ratio on the stress-strain curve of the dual-phase steel is small in the elastic part,while it is obvious in the plastic part.In the plastic part of this curve,the strain decreases with the increase of f_M,while it decreases with the decrease of the yield stress ratio.
基金financially supported by the National Natural Science Foundation of China(No.50904006)the Fundamental Research Funds for the Central Universities of China(No.FRT-TP-10-001A)
文摘The microstructures and mechanical properties of C-Mn-Cr-Nb and C-Mn-Si-Nb ultra-high strength dual-phase steels were studied by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and tensile test. The results show that Si can promote the transformation of austenite （γ） to ferrite （α）, enlarge the （α＋γ） region, and increase the aging stability of martensite by inhibiting carbide precipitation. Adding Cr leads to the formation of retained austenite and martensite/austenite （M/A） constituents, as well as the decomposi- tion of martensite during the overaging stage. Both of the steels show higher initial strain-hardening rates and two-stage strain-hardening characteristics. The C-Mn-Si-Nb steel shows the higher strain-hardening rate than the C-Mn-Cr-Nb steel in the first stage; however, there is no significant difference in the second stage. Although the tensile strength and elongation of the two steels both exceed 1000 MPa and 15%, respectively, the comprehensive mechanical properties of the C-Mn-Si-Nb steel are superior.
基金financially supported by the National Natural Science Foundation of China (Nos.U1360202,51472030,and 51502014)
文摘A C–Mn dual-phase steel was soaked at 800°C for 90 s and then either rapidly cooled to 450°C and held for 30 s(process A) or rapidly cooled to 350°C and then reheated to 450°C(process B) to simulate the hot-dip galvanizing process. The influence of the hot-dip galvanizing process on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel(DP600) was investigated using optical microscopy, scanning electron microscopy(SEM), transmission electron microscopy(TEM), and tensile tests. The results showed that, in the case of process A, the microstructure of DP600 was composed of ferrite, martensite, and a small amount of bainite. The granular bainite was formed in the hot-dip galvanizing stage, and martensite islands were formed in the final cooling stage after hot-dip galvanizing. By contrast, in the case of process B, the microstructure of the DP600 was composed of ferrite, martensite, bainite, and cementite. In addition, compared with the yield strength(YS) of the DP600 annealed by process A, that for the DP600 annealed by process B increased by approximately 50 MPa because of the tempering of the martensite formed during rapid cooling. The work-hardening coefficient(n value) of the DP600 steel annealed by process B clearly decreased because the increase of the YS affected the computation result for the n value. However, the ultimate tensile strength(UTS) and elongation(A80) of the DP600 annealed by process B exhibited less variation compared with those of the DP600 annealed by process A. Therefore, DP600 with excellent comprehensive mechanical properties(YS = 362 MPa, UTS = 638 MPa, A_(80) = 24.3%, n = 0.17) was obtained via process A.
基金F.Guo thanks for the support of Chongqing Research Program of Basic Research and Frontier Technology Scientific Research(cstc2019jcyj-msxmX0111)University Innovation Research Group of Chongqing(CXQT20023)+1 种基金Scientific Research Foundation of Chongqing University of Technology(2017ZD35)L.Y.Jiang is sponsored by Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN201901127).
文摘Dual-phase Mg-Li alloys sheets were rolled at four different temperatures ranging from liquid nitrogen to 300℃to explore effect of rolling temperature on texture and mechanical properties of the material.Crystal plasticity simulation was utilized to illustrate the influence of slip activity on rolling texture development.The results show that the rolling texture is largely depended on deformation temperature.Unlike commercial Mg alloys,the critical resolved shear stress of basal slip inα-Mg phase of Mg-Li alloy decreased more significantly by increasing temperature compared to that of pyramidal<c+a>slip.Enhancement of basal slip by increasing temperature triggered a decrease of split angle of basal poles for the double-peak texture.Prismaticslip largely enhanced by increasing temperature upon 200℃,which induced a wider orientation spread along the transverse direction.For theβ-Li phase,the promotion of{110}<111>slip system at elevated temperature triggered the enhancement of{211}<110>and{111}<211>texture components.The cryo-rolled sample exhibited the highest strength compared to the others due to a strong hardening behavior at this temperature.A two-stage hardening behavior was observed in these as-rolled dual-phase alloys.Strain transition at phase boundaries could be the reason for appearance of this two-stage hardening.
基金Item Sponsored by National Natural Science Foundation of China(50904006)The Fundamental Research Funds for the Central Universities of China(FRT-TP-10-001A)
文摘Low-carbon Cr-Mo micro-alloyed deep drawing dual-phase steels were designed in laboratory. As the mi- crostructure and texture evolution in hot-rolled strips and annealed sheets were investigated using SEM, TEM and XRD technologies, the attribution of solute Mo and MoC particles to DP sheets＇ drawing capacity was investigated. The precipitation thermodynamics were also calculated by Thermo-calc software. Results show that the precipitates in hot-rolled strips mainly are MoC, AIN and MnS, and with the increase of Mo addition, finer and denser MoC par- ticles precipitated in matrix and along grain boundaries of ferrite more easily. Weak textures are shown in the hot- rolled strips, and {112}~110~ and {223}%110~ components tend to be stable in subsequent cold rolling process. During annealing, on one hand, the development of ~lll~//ND texture is suppressed because finer MoC particles prevent the grain boundary migration. On the other hand, unfavorable texture {001 } %110：〉 significantly reduces with Mo increasing, which is attributed to that part of solution C in matrix has been fixed during recrystallization. In addition, the addition of Mo can enhance hardenability strongly and MoC easily re-dissolve at high temperature, which is favor to form martensite in dual-phase steel.
基金supported by the National Natural Science Foundation of China(51004069 and 51474145)the National Science Fund for Distinguished Young Scholars(51225401)
文摘A series of oxygen permeable dual-phase composite oxides 60 wt% Ce0.8Gd0.2O2-δ-40 wt% LnBaCo2O5＋δ （CGO-LBCO, Ln = La, Pr, Nd, Sin, Gd and Y） were synthesized through a sol-gel route and effects of the Ln3＋ cations on their phase structure, oxygen permeability and chemical stability against CO2 were investigated systemically by XRD, SEM, TG-DSC and oxygen permeation experiments. XRD patterns reveal that the larger Ln3＋ cations （La3＋, Pr3＋ and Nd3＋） successfully stabilized the double-layered perovskite structure of sintered LBCO, while the smaller ones （Sm3＋, Gd3＋, and Y3＋） resulted in the partial decomposition of LBCO with some impurities formed. CGO-PBCO yields the highest oxygen permeation flux, reaching 2.8× 10^-7 mol.s-1.cm-2 at 925 ℃ with 1 mm thickness under air/He gradient. The TG-DSC profiles in 20 mol% CO2/N2 and oxygen permeability experiments with CO2 as sweep gas show that CGO-YBCO demonstrates the best chemical stability against CO2, possibly due to its minimum basicity. The stable oxygen permeation flux of CGO-YBCO under CO2 atmosphere reveals its potential application in the oxy-fuel combustion route for CO2 capture.
基金supports from the National Natural Science Foundation of China(No.51871033).
文摘Hardness tests and transmission electron microscopy were used to investigate the strategy of tailoring the phase fraction of precipitates in an Al-Zn-Mg-Cu alloy strengthened by T’ and η’ phases. Different phase fractions of T’ and η’ phases are presented in samples subjected to either single or two stages of ageing treatments at 120 and 150 ℃.For both types of ageing, the precipitation of η’ phase is found to be promoted by ageing at lower temperature and its phase fraction increases with prolonging ageing time at 120 ℃;whereas the phase fractions of T’ and η’ phases almost remain constant during ageing at 150 ℃. Besides, the strain fields produced by T’ and η’ phases were analyzed by using the geometric phase analysis technique, and on a macroscale the contributions of T’ and η’ phases to precipitation strengthening have been quantitatively predicted by combining the size, phase fraction and number density of precipitates.
基金Founded by National Natural Science Foundation of China(No.51004037)Shenyang City Application Basic Research Project(No.F13-316-1-15)State Key Laboratory Opening Project of Northeastern University(No.12SYS05)
文摘Continuous annealing simulation tests were conducted by using a continuous annealing thermomechanical simulator. Holding times of 5, 60, 180, and 480 seconds for an intercritical annealing temperature of 820℃ were adopted to investigate the evolution of the mierostructure and mechanical properties of ferrite-bainite dual-phase steel. The ferrite-bainite dual-phase steel was characterized by high strength and low yield ratio due to the presence of the constituents （polygonal ferrite, bainite, martensite and retained austenite） of the steel microstructure. Specimen 3 exhibits the highest value of A50 （7.67%） and a product of Rm × A50 （10453MPa%） after a 180s holding. This is likely attributed to the presence of a C-enriched retained anstenite in the microstructure. And the effect of martensite islands and carbide precipitate is thought to be able to contribute in strengthening the present steel. It is expected that equilibrium of anstenite fraction would be reached for reasonable intercritical holding period, regardless of the heating temperature. The results suggest that long increasing holding times may not be needed because the major phase of the microstructure does not change very significantly. It is favorable for industrial production of DP steels to shorten holding times. Key words： ferrite-bainite dual-phase steel; holding time; martensite islands; mechanical properties
基金financially supported by the National Key Project of Scientific and Technical Supporting Programs of China (No. 2011BAE13B07)
文摘In a typical process, C-Mn steel was annealed at 800℃ for 180 s, and then cooled rapidly to obtain the ferrite-martensite microstructure. After pre-straining, the specimens were baked and the corresponding bake-hardening （BH） values were determined as a function of pre-strain, baking temperature, and baking time. The influences ofpre-strain, baking temperature and baking time on the microstructure evolution and bake-hardening behavior of the dual-phase steel were investigated systematically. It was found that the BH value apparently increased with an increase in pre-strain in the range from 0 to 1%; however, increasing pre-strain from 1% to 8% led to a decrease in the BH value. Furthermore, an increase in baking temperature favored a gradual improvement in the BH value because of the formation of Cottrell atmosphere and the precipitation of carbides in both the ferrite and martensite phases. The BH value reached a maximum of 110 MPa at a baking temperature of 300℃. Moreover, the BH value enhanced significantly with increasing baking time from 10 to 100 min.
基金the Natural Science Foundation of Shanxi Province,China(Nos.201901D111105 and 201901D111114)Transformation of Scientific and Technological Achievements Programs of Higher Education Institutions in Shanxi Province,China(2019)+2 种基金the Opening Project of the State Key Laboratory of Explosion Science and Technology(Beijing Institute of Technology)(No.KFJJ20-13M)the Graduate Science and Technology Innovation Fund Project of Shanxi Province,China(No.2019BY044)the State Key Lab of Advanced Metals and Materials of China(No.2020-Z09).
文摘The evolution of the microstructure and tensile properties of dual-phase Al0.6CoCrFeNi high-entropy alloys(HEAs)subjected to cold rolling was investigated.The homogenized Al0.6CoCrFeNi alloys consisted of face-centered-cubic and body-centered-cubic phases,presenting similar mechanical behavior as the as-cast state.The yield and tensile strengths of the alloys could be dramatically enhanced to^1205 MPa and^1318 MPa after 50%rolling reduction,respectively.A power-law relationship was discovered between the strain-hardening exponent and rolling reduction.The tensile strengths of this dual-phase HEA with different cold rolling treatments were predicted,mainly based on the Hollomon relationship,by the strain-hardening exponent,and showed good agreement with the experimental results.
基金the National Key R&D Program of China(Grant No.2017YFB0304404)Shandong Provincial Natural Science Foundation of China(Grant No.ZR2018MEM007).
文摘The dynamic tensile behavior and deformation mechanism of ultra-high-strength dual-phase(UHS-DP1000)steel were investigated over a wide range of strain rates from 10^-4 to 10^3 s^-1.As the strain rate increases,the transition strain decreases from 2.73 to 1.92,and the martensite plastic deformation starts earlier.At strain rate of 10^-4-0.5 s^-l,the inhomogeneous plastic deformation ability increases because the dislocation density in the ferrite matrix increases.This leads to a decrease in uni form elongation and an increase in fracture elongation.When the strain rate increases from 0.5 to 500s^-l.the amount of mobile dislocation increases,which is the main reason for the enhancing uniform elongation and fracture elongation.Mea nwhile,because the dislocation motio n resistance rapidly in creases,the yield strength and ultimate tensile strength also increase.When the strain rate is higher than 500 s^-1.the hardening behavior caused by the dislocation motion resistance has not been offset by softening due to the mobile dislocation and adiabatic heating.The voids at the early stage of deformation could not uniformly form and grow,and thus the homogeneous plastic deformation ability decreases.
基金the National Natural Science Foundation of China(Nos.51671012,51831006 and 51971009)the International Science and Technology Cooperation Program of China(No.2015DFA51430)the Fundamental Research Funds for the Central Universities。
文摘In this study,a novel strategy for developingα+βdual-phase titanium alloys with low Young's modulus and high yield strength was proposed,and a Ti-15Nb-5Zr-4Sn-1 Fe alloy was developed through theoretical composition design and microstructure manipulation.After hot-rolling and subsequent annealing,a high volume fraction of ultrafine grainedαphase embedded in metastableβ-matrix was formed in the microstructure as intended.Consequently,this alloy exhibits both low Young's modulus(61 GPa)and high yield strength(912 MPa).The experimental results prove that the proposed strategy is appropriate for developing titanium alloys with superior yield strength-to-modulus ratio than those of conventional metallic biomedical materials.Present study might shed light on the research and development of advanced biomedical titanium alloys with low Young's modulus and high yield strength.
