The phase transformation and mechanical behavior of Ti-43Al-9V-0.2Y alloy under varied heat treatments were systematically investigated.The cooling phase sequence is identified as β→β+α→α→γ+α(α_(2))→β+γ+...The phase transformation and mechanical behavior of Ti-43Al-9V-0.2Y alloy under varied heat treatments were systematically investigated.The cooling phase sequence is identified as β→β+α→α→γ+α(α_(2))→β+γ+α(α_(2))→β(β_(0))+γ.Above 1240℃,slow cooling forms lamellar structures via α→γ+α(α_(2))→β+γ+α(α_(2)),while fast cooling follows α→γ+α→β(β_(0))+γ;below 1240℃,α→γ+α(α_(2))dominates.At 800℃ and 1.0×10^(−4)s^(−1),γphase in duplex microstructures restricts dislocation slip due to low stacking fault energy,promoting dynamic recrystallization.Mixed microstructure(γ/β_(0) lamellar and duplex microstructure)achieves a remarkable strength-ductility product of 4907 MPa%through synergistic effects:the duplex enhances plasticity,while the lamellar improves strength.In both microstructures,limited dislocation slip/climb in β_(0) phases creates dislocation density gradients at γ/β_(0) interfaces,inducing micro-void nucleation and microcracks in β_(0).γ phase impedes defect propagation,and micro-voids further suppress crack growth.The crack propagation in α_(2)/γ lamellar microstructure depends on stress direction:parallel stress hinders crack initiation and growth,while perpendicular stress promotes crack nucleation and expansion.展开更多
Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such a...Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such ashigh-vacuum, high-pressure, and strong magnetic fields compared with the traditional electrical sensing technology.However, with the increasing application requirements, how to further improve the sensitivity of fiber-optic sensors,extend the detection limit and improve the maintenance-free capability has become one of the core issues of thecurrent research. This paper reviews the principle, preparation, and application of fiber-optic microstructured sensingbased on abrupt field type. It specifically outlines the development and applications of micro-nano optical fibers,photonic crystal optical fibers, optical fiber gratings and structured optical fibers, and lists the main preparationmethods of two types of micro-nano optical fibers from the basic theory of optical fiber microstructured sensordevices.展开更多
The influence of homogenization parameters on element segregation,dendritic structure,and the precipitate evolution in the GH3535-0.08wt%Y alloy was investigated.Additionally,some specific homogenization parameters we...The influence of homogenization parameters on element segregation,dendritic structure,and the precipitate evolution in the GH3535-0.08wt%Y alloy was investigated.Additionally,some specific homogenization parameters were maintained constant throughout the experiments.Results indicate that the heat treatment at 1150℃for 10 h is the optimal homogenization condition.Following this optimal treatment,dendrite structures and element segregation are eliminated.Furthermore,both SiC and Y_(5)Si_(3)precipitates in the as-cast alloy decrease significantly.Conversely,the homogenization at 1188℃induces overheating defects within the alloy.Although SiC and Y_(5)Si_(3)phases also decrease,some large M6C phases can still be observed,adversely affecting subsequent forging processes.展开更多
The combustion behavior of Ti-Al-Mo-Zr-Sn-W alloy(TC25G)was studied in a high-temperature and high-speed air flow environment using the laser ignition method combined with ultra-high temperature infrared thermometer,s...The combustion behavior of Ti-Al-Mo-Zr-Sn-W alloy(TC25G)was studied in a high-temperature and high-speed air flow environment using the laser ignition method combined with ultra-high temperature infrared thermometer,scanning electron microscope,X-ray diffractometer,and transmission electron microscope.The burn-resistant performance of TC25G and TC11 alloys was compared.Meanwhile,the microstructural characteristics,crystal structure,and formation mechanism of the combustion products of TC25G alloy were analyzed in detail.The results show that the high-temperature and high-speed air flow promotes combustion within the air flow temperature range of 200–400℃and the air flow velocity range of 0–100 m/s.The combustion path advances along the direction of the air flow.The combustion of TC25G alloy mainly relies on the diffusion of the oxygen and the expansion of the combustion area caused by the movement of the melt.Based on the microstructure and composition of combustion product,it can be divided into the combustion zone,the melting zone,and the heat affected zone.During combustion,the formation of microstructures is closely correlated with the behavior of alloying elements and their selective combination with O.The major oxidation products of Ti are TiO and TiO_(2).The oxides formed by Mo and W hinder the movement of the melt during the combustion.Al and Zr tend to undergo internal oxidation.Al_(2)O_(3)precipitates on the surface of ZrO_(2),forming a protective oxide layer that inhibits the inward diffusion of O.Moreover,the element enrichment at the interface between the melting zone and the heat affected zone increases the melting point on the solid side,hindering the migration of the solid-liquid interface.展开更多
To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator a...To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator at temperatures of 380-440℃and strain rates of 0.05-1 s^(−1).The Johnson-Cook model,Hensel-Spittel model,strain-compensated Arrhenius model,and critical fracture strain model were established.Results show that through the evaluation of the models using the correlation coefficient(R)and the average absolute relative error,the strain-compensated Arrhenius model can represent the flow behavior of the alloy more accurately.Shear bands are more pronounced in the as-homogenized specimens,whereas dynamic recrystallization is predominantly observed in as-rolled specimens.Fracture morphology analysis reveals that a mixed fracture mechanism is prevalent in the as-homogenized specimen,whereas a ductile fracture mechanism is predominant in the as-rolled specimen.The processing maps indicate that the unstable region is reduced in the as-rolled specimens compared with that in the as-homogenized specimens.The optimal hot working windows for the as-homogenized and as-rolled specimens are determined as 410-440℃/0.14-1 s^(−1)and 380-400℃/0.05-0.29 s^(−1),respectively.展开更多
The core-shell structure in bulk TiNb binary alloy was designed and studied by phase-field simulations,where various core-shell structures were obtained by precise control of the initial and boundary conditions of the...The core-shell structure in bulk TiNb binary alloy was designed and studied by phase-field simulations,where various core-shell structures were obtained by precise control of the initial and boundary conditions of the TiNb binary alloy system during spinodal decomposition,and then the formation mechanism of core-shell structure was revealed.In addition,the influences of initial temperature gradient,average temperature,and initial concentration distribution of the system on the core-shell structure were investigated.Results show that the initial concentration gradient is the key factor for forming the core-shell structure.Besides,larger initial temperature gradient and higher average temperature can promote the formation of core-shell structure,which can be stabilized by adjusting the initial concentration distribution of the Nb-rich region in TiNb binary alloy.As a theoretical basis,this research provides a novel and simple strategy for the preparation of TiNb-based alloys and other materials with peculiar core-shell structures and desirable mechanical and physical properties.展开更多
Dissimilar AZ31B magnesium alloy and DC56D steel were welded via AA1060 aluminum alloy by magnetic pulse welding.The effects of primary and secondary welding processes on the welded interface were comparatively invest...Dissimilar AZ31B magnesium alloy and DC56D steel were welded via AA1060 aluminum alloy by magnetic pulse welding.The effects of primary and secondary welding processes on the welded interface were comparatively investigated.Macroscopic morphology,microstructure,and interfacial structure of the joints were analyzed using scanning electron microscope,energy dispersive spectrometer,and X-ray diffractometer(XRD).The results show that magnetic pulse welding of dissimilar Mg/Fe metals is achieved using an Al interlayer,which acts as a bridge for deformation and diffusion.Specifically,the AZ31B/AA1060 interface exhibits a typical wavy morphology,and a transition zone exists at the joint interface,which may result in an extremely complex microstructure.The microstructure of this transition zone differs from that of AZ31B magnesium and 1060 Al alloys,and it is identified as brittle intermetallic compounds(IMCs)Al_(3)Mg_(2) and Al_(12)Mg_(17).The transition zone is mainly distributed on the Al side,with the maximum thickness of Al-side transition layer reaching approximately 13.53μm.Incomplete melting layers with varying thicknesses are observed at the primary weld interface,while micron-sized hole defects appear in the transition zone of the secondary weld interface.The AA1060/DC56D interface is mainly straight,with only a small number of discontinuous transition zones distributed intermittently along the interface.These transition zones are characterized by the presence of the brittle IMC FeAl_(3),with a maximum thickness of about 4μm.展开更多
A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of T...A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of Ti-25Nb (at%) alloy during the dual-track selective laser melting (SLM) process. Simulation results reveal that during the dual-track SLM process, increasing laser power results in greater thermal accumulation, leading to a molten pool of larger volume and coarser grains. Reducing scanning speed enhances remelting and promotes cellular growth at the top of molten pool, whereas faster scanning speed leads to rougher melt tracks and finer grains. Notably, hatch spacing significantly influences the molten pool dimensions and microstructures, and smaller hatch spacing promotes remelting. Furthermore, the orientations of grains in the second track during zigzag scanning differ markedly from those in the first track. More importantly, compared with those after the first track, both the temperature gradient and cooling rate at the boundaries of remelting molten pool are reduced after the second track scanning, resulting in slower interface velocity and significant change in solidification microstructure. This research provides a theoretical foundation for controlling non-equilibrium microstructure and offering novel insights into the optimization of SLM process parameters of titanium alloys.展开更多
In current research,Li_(2)O-Al_(2)O_(3)-SiO_(2)glass-ceramics were prepared by conventional meltquenching and subsequent heat treatment method.The effect of Al_(2)O_(3)content on microstructures,thermal properties,cry...In current research,Li_(2)O-Al_(2)O_(3)-SiO_(2)glass-ceramics were prepared by conventional meltquenching and subsequent heat treatment method.The effect of Al_(2)O_(3)content on microstructures,thermal properties,crystallization behaviours and mechanical properties were investigated.FTIR,Raman spectroscopy and nuclear magnetic resonance spectroscopy microstructure analysis showed that the silico-oxygen network was damaged,while the increase of[AlO_(4)]content repaired the glass network,and finally made the glass network have better connectivity,with the decrease of SiO_(2).The thermal analysis confirmed the increasing glass transition and crystallization temperatures from growing Al_(2)O_(3)content.In addition,different crystal phases can be precipitated in the glass matrix,such as LiAlSi_(4)O_(10),Li_(2)Si_(2)O_(5) in glass with low Al_(2)O_(3)content,the combination of Li_xAl_xSi_(1-x)O_(2),LiAlSi_(3)O_(8),Li_(2)SiO_(3)in glass with intermediate Al_(2)O_(3)content,and the combination of LiAlSi_(2)O_(6),SiO_(2)in glass with high Al_(2)O_(3)content.The hardness of as-prepared glass gradually increases with the increase of the Al_(2)O_(3)content.The Vickers hardness of the glass-ceramics is highly dependent on the Al_(2)O_(3)content in the glass and the heat treatment temperatures,reaching a maximum of 10.11 GPa.Scanning electron microscope images show that the crystals change from spherical to massive and finally to sheet.The change of glass structure,crystal phase and morphology is the main reason for the different mechanical properties.展开更多
In clinical fields with a high risk of infection,such as orthopedics and dentistry,stringent requirements are imposed on the mechanical properties,biocompatibility,and antibacterial performance of biomedical materials...In clinical fields with a high risk of infection,such as orthopedics and dentistry,stringent requirements are imposed on the mechanical properties,biocompatibility,and antibacterial performance of biomedical materials.As an emerging functional biomedical alloy,Titanium-copper(Ti-Cu)alloys have received increasing attention due to their unique composition and microstructure,which endow these materials with favorable mechanical strength,biological activity,and long-lasting antibacterial functionality.However,a systematic summary of the existing research findings remains lacking.In this review,the classification and fundamental properties of Ti-Cu alloys are first outlined.Recent progress in design strategies,fabrication techniques,microstructural characteristics,mechanical behavior,wear resistance,corrosion performance,and biological properties is comprehensively reviewed.Special emphasis is placed on the dual forms of Cu(solid solution Cu and Ti2Cu phase)and their synergistic effects on both mechanical and biological performance.The antibacterial mechanisms and biosafety of Cu are specifically summarized,and its antibacterial efficacy and tissue compatibility are evaluated based on in vitro studies and animal models.Based on these findings,the key challenges associated with the practical application of Ti-Cu alloys are analyzed,and potential directions for optimization and future development are proposed.The review concludes with a concise summary and several forward-looking perspectives.展开更多
The optimization of microstructure represents a significant methodology for enhancing coercivity(Hcj).This paper concentrates on optimizing the microstructure of magnets through the manipulation of the composition of ...The optimization of microstructure represents a significant methodology for enhancing coercivity(Hcj).This paper concentrates on optimizing the microstructure of magnets through the manipulation of the composition of low-melting-point and high-melting-point elements,thereby achieving the objective of augmenting the comprehensive magnetic properties of magnets.The present study is concerned with the microstructure of magnets comprising three distinct Ga and B contents,and the associated changes in their magnetic properties.The findings indicate that when the Ga content is 0.5 wt%and the B content is 0.88 wt%,the coercivity of the magnets is markedly enhanced.This is evidenced by an increase in coercivity from 8.51 to 14.83 kOe,representing a 74.26%rise.Concurrently,the residual magnetization strength of the magnet remains unaltered.This finding provides a crucial foundation for optimizing the overall magnetic properties of the magnets.The microstructural analysis indicates that a reduction in B content coupled with an increase in Ga content leads to the melting of sharp angles on the surface of the main-phase grains,facilitated by low-melting-point rare-earth-rich phases.This process results in the migration of Fe from the grain boundaries(GBs)to the triple junction phases(TJPs),while Nd migrates from the TJPs to the GBs.This migration results in a reduction in the agglomeration of rare-earth-rich elements within the TJPs,thereby increasing the Nd content in the GBs.This increase enhances the wettability of the GBs,while the reduction of Fe content in this phase mitigates the exchange-coupling effect between the main-phase GBs.Consequently,the GBs become more smooth,more homogeneous and more continuous,which ultimately results in an enhancement of the coercivity of the magnets.展开更多
Heterogeneous nucleation,characterized by its low nucleation barrier and controllable nucleation sites,has been widely employed to manipulate the microstructures and properties of metallic materials.In recent years,th...Heterogeneous nucleation,characterized by its low nucleation barrier and controllable nucleation sites,has been widely employed to manipulate the microstructures and properties of metallic materials.In recent years,the dispersion of inclusions,carbides,and microstructure refinement in steel have emerged as one of the key research directions in the development of high-quality steel.The current research status regarding the regulation of inclusions,carbides,and microstructures in steel through heterogeneous nucleation are reviewed.The key points and challenges in refining the second phase and microstructure in steel using inclusion particles are highlighted,aiming to provide inspiration and references for future scholars.Deoxidized inclusions,when refined and dispersed,exhibit favorable lattice matching with second phases(e.g.,nitrides,sulfides,carbides)in steel.This characteristic serves as the fundamental mechanism for achieving refinement of the second phase.Concurrently,the solid-solution alloying effect from deoxidizing metals contributes to second-phase refinement,an aspect that requires prioritized investigation.In addition to the single heterogeneous nucleation refinement effect,the two-stage heterogeneous nucleation refinement of the second phase and microstructure offers a new approach for follow-up research.Notably,second-phase particles added as heterogeneous nucleation sites via external addition often require surface modification to ensure their stable retention in steel at high temperatures,which remains a major challenge restricting the widespread application of this method.Currently,the explanation of heterogeneous nucleation phenomena primarily relies on empirical calculations of lattice mismatch between the substrate and the nucleating phase,which cannot fully elucidate the quantitative relationship on the interface between the substrate and the nucleation phase.On this basis,quantifying the electronic structure and nucleation barrier at the interface between the substrate and the nucleation phase is a critical direction worthy of increased attention in the future.展开更多
An industrial scale test was conducted to investigate the effects of no treatment,Ca treatment,Ce treatment and Ca+Ce composite treatment on the modification of inclusions,microstructure and mechanical properties of A...An industrial scale test was conducted to investigate the effects of no treatment,Ca treatment,Ce treatment and Ca+Ce composite treatment on the modification of inclusions,microstructure and mechanical properties of Al-killed Q355B steel.Results showed that the stability of the continuous casting process was improved when Ca pretreatment was added before Ce treatment compared to Ce treatment alone.After Ca+Ce composite treatment,the lowest total oxygen content and average diameter,lower number density and the smallest aspect ratio of inclusions were obtained.The thermodynamic calculations showed that the phases stabilized under the Ce-treated and Ca+Ce composite-treated steel compositions were Al_(11)O_(18)Ce+CeAlO_(3) and CeAlO_(3)+CaO–Al_(2)O_(3)+liquid inclusion,respectively.It was also found that the oxygen content in the steel affects the Ce modification on inclusions and needs to be reduced before modification.The Ca to Ce ratio had a large effect on the composition of inclusions in the case of Ca+Ce composite treatments.Furthermore,adding rare earth Ce could effectively refine the solidification structure,improve micro-segregation,and also obtain finer equiaxed ferrite grains and dense pearlite lamellar structure.Moreover,a small amount of Ce treatment does not have a significant effect on the strength of the steel,but higher cleanliness and finer organization can have a positive effect on the plasticity and toughness of the material.展开更多
A critical scientific gap exists in quantifying the intrinsic mechanisms of shale mechanical property degradation induced by the combined effects of perforation(impact)and acidization—two core techniques for shale re...A critical scientific gap exists in quantifying the intrinsic mechanisms of shale mechanical property degradation induced by the combined effects of perforation(impact)and acidization—two core techniques for shale reservoir permeability enhancement.To address this gap,this study proposed an innovative coupled experimental framework integrating dynamic-static cyclic loading(to simulate perforation impact)and acid erosion.Static uniaxial compression tests were performed on treated damaged shale samples,with microstructural characterization via X-ray diffraction(XRD)and scanning electron microscopy(SEM).Key findings include:(1)The damage factor(characterized by longitudinal wave velocity)showed a significant positive correlation with acid concentration;(2)Combined damage(impact+acidization)caused far more severe mechanical deterioration than single damage modes—for instance,samples under combined damage with 20%hydrochloric acid exhibited a strength reduction to 158.97 MPa,with sharp decreases in peak strength and elastic modulus;(3)Damage reduced total energy and elastic strain energy of samples while increasing dissipated energy proportion,leading to more developed internal fractures and severe failure in combined damage samples;(4)Acidization promoted sample fragmentation into smaller debris,resulting in significantly higher fractal dimensions of acidized shale than other damage types under the same acid concentration;(5)XRD and SEM analyses confirmed that high-concentration acid erosion reduced shale carbonate content,and the synergy of mechanical pre-damage and chemical dissolution in combined damage accelerated acid-rock reactions,significantly increasing micro-interfacial pores and degrading shale structural integrity.This study’s innovation lies in establishing a coupled experimental framework that reproduces the actual“perforation-acidization”sequence,quantitatively revealing the synergistic degradation mechanism of shale mechanical properties under combined damage—providing a novel theoretical basis for optimizing shale reservoir stimulation parameters.展开更多
The microstructure of high Nb-TiAl alloys was optimized by the addition of a small amount of Ta elements to further improve their properties.A series of Ti46Al1.5Cr8Nb-xTa(x=0.2,0.4,0.6,0.8,1.0,at.%)alloys were prepar...The microstructure of high Nb-TiAl alloys was optimized by the addition of a small amount of Ta elements to further improve their properties.A series of Ti46Al1.5Cr8Nb-xTa(x=0.2,0.4,0.6,0.8,1.0,at.%)alloys were prepared by vacuum arc melting.The microstructure,mechanical properties,and related influencing mechanisms were systematically investigated.The results indicate that the solidification microstructure of the Ti46Al1.5Cr8Nb-xTa alloys comprises theγ-TiAl phase,α_(2)-Ti_(3)Al phase,and B2 phase.As the Ta content increases from 0.2 at.%to 1.0 at.%,the content ofα_(2)phase and B2 phase increases,while theγphase content decreases.Among them,the B2 phase shows the most pronounced change,being significantly refined,with its content increasing from 12.49%to 21.91%.In addition,the average size of the lamellar colony decreases from 160.65 to 94.44μm.The addition of the Ta element shifts the solidification path toward lower aluminum concentrations,leading to changes in phase content.The tantalum-induced increase in the B2 phase and enhanced supercooling at the solidification front provide the basis for lamellar colony refinement.Compressive testing at room temperature reveals that the Ti46 Al1.5 Cr8 Nb0.4 Ta alloy exhibits optimal compressive properties,achieving a compressive strength of 2,434 MPa and a compressive strain of 33.1%.The improvement of its properties is attributed to a combination of lamellar colony refinement,solid solution strengthening resulting from the incorporation of Ta element,and a reduction in the c/a of theγphase.展开更多
Quantitative analysis of aluminum-silicon(Al-Si)alloy microstructure is crucial for evaluating and controlling alloy performance.Conventional analysis methods rely on manual segmentation,which is inefficient and subje...Quantitative analysis of aluminum-silicon(Al-Si)alloy microstructure is crucial for evaluating and controlling alloy performance.Conventional analysis methods rely on manual segmentation,which is inefficient and subjective,while fully supervised deep learning approaches require extensive and expensive pixel-level annotated data.Furthermore,existing semi-supervised methods still face challenges in handling the adhesion of adjacent primary silicon particles and effectively utilizing consistency in unlabeled data.To address these issues,this paper proposes a novel semi-supervised framework for Al-Si alloy microstructure image segmentation.First,we introduce a Rotational Uncertainty Correction Strategy(RUCS).This strategy employs multi-angle rotational perturbations andMonte Carlo sampling to assess prediction consistency,generating a pixel-wise confidence weight map.By integrating this map into the loss function,the model dynamically focuses on high-confidence regions,thereby improving generalization ability while reducing manual annotation pressure.Second,we design a Boundary EnhancementModule(BEM)to strengthen boundary feature extraction through erosion difference and multi-scale dilated convolutions.This module guides the model to focus on the boundary regions of adjacent particles,effectively resolving particle adhesion and improving segmentation accuracy.Systematic experiments were conducted on the Aluminum-Silicon Alloy Microstructure Dataset(ASAD).Results indicate that the proposed method performs exceptionally well with scarce labeled data.Specifically,using only 5%labeled data,our method improves the Jaccard index and Adjusted Rand Index(ARI)by 2.84 and 1.57 percentage points,respectively,and reduces the Variation of Information(VI)by 8.65 compared to stateof-the-art semi-supervised models,approaching the performance levels of 10%labeled data.These results demonstrate that the proposed method significantly enhances the accuracy and robustness of quantitative microstructure analysis while reducing annotation costs.展开更多
Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic ...Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic rolled SF-7055 Al alloy is elongated to form a fiber texture.Numerous proliferating dislocations in the microstructure accumulate into dislocation walls and cells,and eventually form subgrains.These subgrain boundaries divide the original grain,thereby reducing the grain size.Under severe deformation conditions,they even enable the formation of nanograins.Meanwhile,the Cu-rich precipitates in the matrix are also broken and refined under the action of large rolling stress.In the process of cryogenic rolling,the tensile strength and hardness of SF-7055 Al alloy gradually increase,while the plasticity decreases.Moreover,the fracture morphology of cryogenic rolled SF-7055 Al alloy gradually transforms to the ductile and quasi-cleavage hybrid fracture characteristics with increased reduction.展开更多
The Cu-12Fe alloy has attracted significant attention due to its excellent electrical conductivity and electromagnetic shielding capability,high strength,cost-effectiveness,and recyclability.In the present work,the Cu...The Cu-12Fe alloy has attracted significant attention due to its excellent electrical conductivity and electromagnetic shielding capability,high strength,cost-effectiveness,and recyclability.In the present work,the Cu-12Fe alloy strip with the thickness of 2.4 mm was successfully produced by twin-roll strip casting.The microstructure and properties of the Cu-12Fe alloy were tailored by cold rolling and aging treatment.The tensile strength of the as-cast strip is approximately 328 MPa and its elongation is 25%.The Fe phase randomly dispersed in the matrix,and the average size of Fe-rich phase is 2μm.Besides,enrichment of Fe phase is observed in the central layer of the strip,results in the formation of the“sandwich structure”.Moreover,the as-cast strip of Cu-12Fe was directly cold-rolled from 2.4 to 0.12 mm.The directly cold-rolled sample after aging at 450℃for 16 h(ProcessⅠ)shows excellent electrical conductivity of 69.5%IACS,the tensile strength and elongation are 513 MPa and 3.8%,the saturation magnetic flux density is 20.1 emu·g^(-1),and the coercive force is 25.2 Oe.In ProcessⅡ,the as-cast strip firstly cold-rolled to 1.2 mm,then aged at 500℃for 1.5 h,followed by cold rolling to 0.12 mm,finally aged at 450℃for 16 h.The sample after ProcessⅡshows the electrical conductivity of 66.3%IACS,the tensile strength of 533 MPa,an elongation of 3.5%,saturation magnetic flux density of 21.4 emu·g^(-1),and the coercive force of 22.3 Oe.展开更多
The rapid advancements in computer vision(CV)technology have transformed the traditional approaches to material microstructure analysis.This review outlines the history of CV and explores the applications of deep-lear...The rapid advancements in computer vision(CV)technology have transformed the traditional approaches to material microstructure analysis.This review outlines the history of CV and explores the applications of deep-learning(DL)-driven CV in four key areas of materials science:microstructure-based performance prediction,microstructure information generation,microstructure defect detection,and crystal structure-based property prediction.The CV has significantly reduced the cost of traditional experimental methods used in material performance prediction.Moreover,recent progress made in generating microstructure images and detecting microstructural defects using CV has led to increased efficiency and reliability in material performance assessments.The DL-driven CV models can accelerate the design of new materials with optimized performance by integrating predictions based on both crystal and microstructural data,thereby allowing for the discovery and innovation of next-generation materials.Finally,the review provides insights into the rapid interdisciplinary developments in the field of materials science and future prospects.展开更多
The laser-clad Fe45 alloy coating inherently comprises multiple crystalline phases,resulting in a heterogeneous microstructural distribution that influences its performance.In this study,the rare earth yttria(Y_(2)O_(...The laser-clad Fe45 alloy coating inherently comprises multiple crystalline phases,resulting in a heterogeneous microstructural distribution that influences its performance.In this study,the rare earth yttria(Y_(2)O_(3))was employed to modify laser-clad Fe45 alloy coatings,and the effects of Y_(2)O_(3) addition on their microstructure,microhardness,and tribological properties were investigated.As the Y_(2)O_(3) content increases from 0%to 0.3wt.%,the dominant microstructure transforms from columnar crystals to fine cellular and equiaxed crystals.The modified coating with 0.3wt.%Y_(2)O_(3) achieves a surface hardness of 568 HV_(0.3)and a wear volume of 1,735.41 um~3,representing a 14.06%increase in hardness and a 51.16%reduction in wear volume compared to the undoped coating.Further increasing the Y_(2)O_(3) content from 0.3wt.%to 0.9wt.%gradually leads to the emergence of a coarser feather-like microstructure,characterized by a dendritic framework with inter-dendritic equiaxed crystals.Concurrently,both the hardness and wear resistance of the coating decrease.Nevertheless,all Y_(2)O_(3)-modified coatings surpass the undoped Fe45 coating in both hardness and wear resistance.Appropriate Y_(2)O_(3) doping effectively refines the Fe45 alloy coating's microstru cture and induces lattice distortion,thereby enhancing its hardness and wear resistance.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52201035 and FRF-TP-24-010A).
文摘The phase transformation and mechanical behavior of Ti-43Al-9V-0.2Y alloy under varied heat treatments were systematically investigated.The cooling phase sequence is identified as β→β+α→α→γ+α(α_(2))→β+γ+α(α_(2))→β(β_(0))+γ.Above 1240℃,slow cooling forms lamellar structures via α→γ+α(α_(2))→β+γ+α(α_(2)),while fast cooling follows α→γ+α→β(β_(0))+γ;below 1240℃,α→γ+α(α_(2))dominates.At 800℃ and 1.0×10^(−4)s^(−1),γphase in duplex microstructures restricts dislocation slip due to low stacking fault energy,promoting dynamic recrystallization.Mixed microstructure(γ/β_(0) lamellar and duplex microstructure)achieves a remarkable strength-ductility product of 4907 MPa%through synergistic effects:the duplex enhances plasticity,while the lamellar improves strength.In both microstructures,limited dislocation slip/climb in β_(0) phases creates dislocation density gradients at γ/β_(0) interfaces,inducing micro-void nucleation and microcracks in β_(0).γ phase impedes defect propagation,and micro-voids further suppress crack growth.The crack propagation in α_(2)/γ lamellar microstructure depends on stress direction:parallel stress hinders crack initiation and growth,while perpendicular stress promotes crack nucleation and expansion.
基金support by National Natural Science Foundation of China (Nos. 51606158, 12104402)
文摘Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such ashigh-vacuum, high-pressure, and strong magnetic fields compared with the traditional electrical sensing technology.However, with the increasing application requirements, how to further improve the sensitivity of fiber-optic sensors,extend the detection limit and improve the maintenance-free capability has become one of the core issues of thecurrent research. This paper reviews the principle, preparation, and application of fiber-optic microstructured sensingbased on abrupt field type. It specifically outlines the development and applications of micro-nano optical fibers,photonic crystal optical fibers, optical fiber gratings and structured optical fibers, and lists the main preparationmethods of two types of micro-nano optical fibers from the basic theory of optical fiber microstructured sensordevices.
基金National Natural Science Foundation of China(51801227,52071331)。
文摘The influence of homogenization parameters on element segregation,dendritic structure,and the precipitate evolution in the GH3535-0.08wt%Y alloy was investigated.Additionally,some specific homogenization parameters were maintained constant throughout the experiments.Results indicate that the heat treatment at 1150℃for 10 h is the optimal homogenization condition.Following this optimal treatment,dendrite structures and element segregation are eliminated.Furthermore,both SiC and Y_(5)Si_(3)precipitates in the as-cast alloy decrease significantly.Conversely,the homogenization at 1188℃induces overheating defects within the alloy.Although SiC and Y_(5)Si_(3)phases also decrease,some large M6C phases can still be observed,adversely affecting subsequent forging processes.
基金China“Ye Qisun”Science Foundation Project of National Natural Science Foundation(U2141222)Innovation Fund(8F231527Z)。
文摘The combustion behavior of Ti-Al-Mo-Zr-Sn-W alloy(TC25G)was studied in a high-temperature and high-speed air flow environment using the laser ignition method combined with ultra-high temperature infrared thermometer,scanning electron microscope,X-ray diffractometer,and transmission electron microscope.The burn-resistant performance of TC25G and TC11 alloys was compared.Meanwhile,the microstructural characteristics,crystal structure,and formation mechanism of the combustion products of TC25G alloy were analyzed in detail.The results show that the high-temperature and high-speed air flow promotes combustion within the air flow temperature range of 200–400℃and the air flow velocity range of 0–100 m/s.The combustion path advances along the direction of the air flow.The combustion of TC25G alloy mainly relies on the diffusion of the oxygen and the expansion of the combustion area caused by the movement of the melt.Based on the microstructure and composition of combustion product,it can be divided into the combustion zone,the melting zone,and the heat affected zone.During combustion,the formation of microstructures is closely correlated with the behavior of alloying elements and their selective combination with O.The major oxidation products of Ti are TiO and TiO_(2).The oxides formed by Mo and W hinder the movement of the melt during the combustion.Al and Zr tend to undergo internal oxidation.Al_(2)O_(3)precipitates on the surface of ZrO_(2),forming a protective oxide layer that inhibits the inward diffusion of O.Moreover,the element enrichment at the interface between the melting zone and the heat affected zone increases the melting point on the solid side,hindering the migration of the solid-liquid interface.
文摘To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator at temperatures of 380-440℃and strain rates of 0.05-1 s^(−1).The Johnson-Cook model,Hensel-Spittel model,strain-compensated Arrhenius model,and critical fracture strain model were established.Results show that through the evaluation of the models using the correlation coefficient(R)and the average absolute relative error,the strain-compensated Arrhenius model can represent the flow behavior of the alloy more accurately.Shear bands are more pronounced in the as-homogenized specimens,whereas dynamic recrystallization is predominantly observed in as-rolled specimens.Fracture morphology analysis reveals that a mixed fracture mechanism is prevalent in the as-homogenized specimen,whereas a ductile fracture mechanism is predominant in the as-rolled specimen.The processing maps indicate that the unstable region is reduced in the as-rolled specimens compared with that in the as-homogenized specimens.The optimal hot working windows for the as-homogenized and as-rolled specimens are determined as 410-440℃/0.14-1 s^(−1)and 380-400℃/0.05-0.29 s^(−1),respectively.
基金National Natural Science Foundation of China(12372152)Guangdong Basic and Applied Basic Research Foundation(2023A1515011819,2024A1515012469)Shandong Provincial Natural Science Foundation(ZR2023MA058)。
文摘The core-shell structure in bulk TiNb binary alloy was designed and studied by phase-field simulations,where various core-shell structures were obtained by precise control of the initial and boundary conditions of the TiNb binary alloy system during spinodal decomposition,and then the formation mechanism of core-shell structure was revealed.In addition,the influences of initial temperature gradient,average temperature,and initial concentration distribution of the system on the core-shell structure were investigated.Results show that the initial concentration gradient is the key factor for forming the core-shell structure.Besides,larger initial temperature gradient and higher average temperature can promote the formation of core-shell structure,which can be stabilized by adjusting the initial concentration distribution of the Nb-rich region in TiNb binary alloy.As a theoretical basis,this research provides a novel and simple strategy for the preparation of TiNb-based alloys and other materials with peculiar core-shell structures and desirable mechanical and physical properties.
文摘Dissimilar AZ31B magnesium alloy and DC56D steel were welded via AA1060 aluminum alloy by magnetic pulse welding.The effects of primary and secondary welding processes on the welded interface were comparatively investigated.Macroscopic morphology,microstructure,and interfacial structure of the joints were analyzed using scanning electron microscope,energy dispersive spectrometer,and X-ray diffractometer(XRD).The results show that magnetic pulse welding of dissimilar Mg/Fe metals is achieved using an Al interlayer,which acts as a bridge for deformation and diffusion.Specifically,the AZ31B/AA1060 interface exhibits a typical wavy morphology,and a transition zone exists at the joint interface,which may result in an extremely complex microstructure.The microstructure of this transition zone differs from that of AZ31B magnesium and 1060 Al alloys,and it is identified as brittle intermetallic compounds(IMCs)Al_(3)Mg_(2) and Al_(12)Mg_(17).The transition zone is mainly distributed on the Al side,with the maximum thickness of Al-side transition layer reaching approximately 13.53μm.Incomplete melting layers with varying thicknesses are observed at the primary weld interface,while micron-sized hole defects appear in the transition zone of the secondary weld interface.The AA1060/DC56D interface is mainly straight,with only a small number of discontinuous transition zones distributed intermittently along the interface.These transition zones are characterized by the presence of the brittle IMC FeAl_(3),with a maximum thickness of about 4μm.
基金Guangdong Basic and Applied Basic Research Foundation (2024A1515011873)Shenzhen Basic Research Project (JCYJ20241202123504007)Shenzhen Science and Technology Innovation Commission (KJZD20240903101400001, KJZD20240903102006009)。
文摘A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of Ti-25Nb (at%) alloy during the dual-track selective laser melting (SLM) process. Simulation results reveal that during the dual-track SLM process, increasing laser power results in greater thermal accumulation, leading to a molten pool of larger volume and coarser grains. Reducing scanning speed enhances remelting and promotes cellular growth at the top of molten pool, whereas faster scanning speed leads to rougher melt tracks and finer grains. Notably, hatch spacing significantly influences the molten pool dimensions and microstructures, and smaller hatch spacing promotes remelting. Furthermore, the orientations of grains in the second track during zigzag scanning differ markedly from those in the first track. More importantly, compared with those after the first track, both the temperature gradient and cooling rate at the boundaries of remelting molten pool are reduced after the second track scanning, resulting in slower interface velocity and significant change in solidification microstructure. This research provides a theoretical foundation for controlling non-equilibrium microstructure and offering novel insights into the optimization of SLM process parameters of titanium alloys.
基金Funded by the National Key Research Program(No.2024-1129-954-112)National Natural Science Foundation of China(No.52372033)Guangxi Science and Technology Major Program(No.AA24263054)。
文摘In current research,Li_(2)O-Al_(2)O_(3)-SiO_(2)glass-ceramics were prepared by conventional meltquenching and subsequent heat treatment method.The effect of Al_(2)O_(3)content on microstructures,thermal properties,crystallization behaviours and mechanical properties were investigated.FTIR,Raman spectroscopy and nuclear magnetic resonance spectroscopy microstructure analysis showed that the silico-oxygen network was damaged,while the increase of[AlO_(4)]content repaired the glass network,and finally made the glass network have better connectivity,with the decrease of SiO_(2).The thermal analysis confirmed the increasing glass transition and crystallization temperatures from growing Al_(2)O_(3)content.In addition,different crystal phases can be precipitated in the glass matrix,such as LiAlSi_(4)O_(10),Li_(2)Si_(2)O_(5) in glass with low Al_(2)O_(3)content,the combination of Li_xAl_xSi_(1-x)O_(2),LiAlSi_(3)O_(8),Li_(2)SiO_(3)in glass with intermediate Al_(2)O_(3)content,and the combination of LiAlSi_(2)O_(6),SiO_(2)in glass with high Al_(2)O_(3)content.The hardness of as-prepared glass gradually increases with the increase of the Al_(2)O_(3)content.The Vickers hardness of the glass-ceramics is highly dependent on the Al_(2)O_(3)content in the glass and the heat treatment temperatures,reaching a maximum of 10.11 GPa.Scanning electron microscope images show that the crystals change from spherical to massive and finally to sheet.The change of glass structure,crystal phase and morphology is the main reason for the different mechanical properties.
基金supported by the National Natural Science Foundation of China(Grant No.52401084)the Regional Science Foundation Project of National Natural Science Foundation of China(Grant No.32160209)+3 种基金the Doctoral Research Project Funded by Guizhou Normal University(Grant No.GZNUD[2024]03)the Science and Technology Planning Project of Guizhou Province(Grant Nos.Qian Ke He Foundation-[2024]Youth355,Qian Ke He Foundation-ZK[2024]General442)the Young Elite Scientist Sponsorship Program by GAST(Grand No.GASTYE202408)the Guangxi Natural Science Foundation Joint Special Project(Youjiang Medical University for Nationalities Special Project)(Grant No.2025GXNSFHA069017).
文摘In clinical fields with a high risk of infection,such as orthopedics and dentistry,stringent requirements are imposed on the mechanical properties,biocompatibility,and antibacterial performance of biomedical materials.As an emerging functional biomedical alloy,Titanium-copper(Ti-Cu)alloys have received increasing attention due to their unique composition and microstructure,which endow these materials with favorable mechanical strength,biological activity,and long-lasting antibacterial functionality.However,a systematic summary of the existing research findings remains lacking.In this review,the classification and fundamental properties of Ti-Cu alloys are first outlined.Recent progress in design strategies,fabrication techniques,microstructural characteristics,mechanical behavior,wear resistance,corrosion performance,and biological properties is comprehensively reviewed.Special emphasis is placed on the dual forms of Cu(solid solution Cu and Ti2Cu phase)and their synergistic effects on both mechanical and biological performance.The antibacterial mechanisms and biosafety of Cu are specifically summarized,and its antibacterial efficacy and tissue compatibility are evaluated based on in vitro studies and animal models.Based on these findings,the key challenges associated with the practical application of Ti-Cu alloys are analyzed,and potential directions for optimization and future development are proposed.The review concludes with a concise summary and several forward-looking perspectives.
基金Project supported by the National Key Research and Development Program of China(2022YFB3503302)the Major Projects in Inner Mongolia Autonomous Region(20212D0035)the High-quality Development Special Funds Program Ministry of Industry Technology(TC220H06G)。
文摘The optimization of microstructure represents a significant methodology for enhancing coercivity(Hcj).This paper concentrates on optimizing the microstructure of magnets through the manipulation of the composition of low-melting-point and high-melting-point elements,thereby achieving the objective of augmenting the comprehensive magnetic properties of magnets.The present study is concerned with the microstructure of magnets comprising three distinct Ga and B contents,and the associated changes in their magnetic properties.The findings indicate that when the Ga content is 0.5 wt%and the B content is 0.88 wt%,the coercivity of the magnets is markedly enhanced.This is evidenced by an increase in coercivity from 8.51 to 14.83 kOe,representing a 74.26%rise.Concurrently,the residual magnetization strength of the magnet remains unaltered.This finding provides a crucial foundation for optimizing the overall magnetic properties of the magnets.The microstructural analysis indicates that a reduction in B content coupled with an increase in Ga content leads to the melting of sharp angles on the surface of the main-phase grains,facilitated by low-melting-point rare-earth-rich phases.This process results in the migration of Fe from the grain boundaries(GBs)to the triple junction phases(TJPs),while Nd migrates from the TJPs to the GBs.This migration results in a reduction in the agglomeration of rare-earth-rich elements within the TJPs,thereby increasing the Nd content in the GBs.This increase enhances the wettability of the GBs,while the reduction of Fe content in this phase mitigates the exchange-coupling effect between the main-phase GBs.Consequently,the GBs become more smooth,more homogeneous and more continuous,which ultimately results in an enhancement of the coercivity of the magnets.
基金supported by the National Natural Science Foundation of China(No.52304358)Young Elite Scientists Sponsorship Program by CAST(No.YESS20230462).
文摘Heterogeneous nucleation,characterized by its low nucleation barrier and controllable nucleation sites,has been widely employed to manipulate the microstructures and properties of metallic materials.In recent years,the dispersion of inclusions,carbides,and microstructure refinement in steel have emerged as one of the key research directions in the development of high-quality steel.The current research status regarding the regulation of inclusions,carbides,and microstructures in steel through heterogeneous nucleation are reviewed.The key points and challenges in refining the second phase and microstructure in steel using inclusion particles are highlighted,aiming to provide inspiration and references for future scholars.Deoxidized inclusions,when refined and dispersed,exhibit favorable lattice matching with second phases(e.g.,nitrides,sulfides,carbides)in steel.This characteristic serves as the fundamental mechanism for achieving refinement of the second phase.Concurrently,the solid-solution alloying effect from deoxidizing metals contributes to second-phase refinement,an aspect that requires prioritized investigation.In addition to the single heterogeneous nucleation refinement effect,the two-stage heterogeneous nucleation refinement of the second phase and microstructure offers a new approach for follow-up research.Notably,second-phase particles added as heterogeneous nucleation sites via external addition often require surface modification to ensure their stable retention in steel at high temperatures,which remains a major challenge restricting the widespread application of this method.Currently,the explanation of heterogeneous nucleation phenomena primarily relies on empirical calculations of lattice mismatch between the substrate and the nucleating phase,which cannot fully elucidate the quantitative relationship on the interface between the substrate and the nucleation phase.On this basis,quantifying the electronic structure and nucleation barrier at the interface between the substrate and the nucleation phase is a critical direction worthy of increased attention in the future.
基金funding support from the Special Funding Projects for Local Science and Technology Development guided by the Central Committee(No.2024ZY0050)Guangdong Province Basic and Applied Basic Research Fund Project(No.2024A1515240031).
文摘An industrial scale test was conducted to investigate the effects of no treatment,Ca treatment,Ce treatment and Ca+Ce composite treatment on the modification of inclusions,microstructure and mechanical properties of Al-killed Q355B steel.Results showed that the stability of the continuous casting process was improved when Ca pretreatment was added before Ce treatment compared to Ce treatment alone.After Ca+Ce composite treatment,the lowest total oxygen content and average diameter,lower number density and the smallest aspect ratio of inclusions were obtained.The thermodynamic calculations showed that the phases stabilized under the Ce-treated and Ca+Ce composite-treated steel compositions were Al_(11)O_(18)Ce+CeAlO_(3) and CeAlO_(3)+CaO–Al_(2)O_(3)+liquid inclusion,respectively.It was also found that the oxygen content in the steel affects the Ce modification on inclusions and needs to be reduced before modification.The Ca to Ce ratio had a large effect on the composition of inclusions in the case of Ca+Ce composite treatments.Furthermore,adding rare earth Ce could effectively refine the solidification structure,improve micro-segregation,and also obtain finer equiaxed ferrite grains and dense pearlite lamellar structure.Moreover,a small amount of Ce treatment does not have a significant effect on the strength of the steel,but higher cleanliness and finer organization can have a positive effect on the plasticity and toughness of the material.
基金funded by the National Natural Science Foundation of China(No.52474120)the National Key Research and Development Program of China—2023 Key Special Project(No.2023YFC2907400)+1 种基金the Fundamental Research Funds for the Central Universities(No.2023CXQD045)the Hunan Provincial Natural Science Foundation for Distinguished Young Scholars(No.2023JJ10072).
文摘A critical scientific gap exists in quantifying the intrinsic mechanisms of shale mechanical property degradation induced by the combined effects of perforation(impact)and acidization—two core techniques for shale reservoir permeability enhancement.To address this gap,this study proposed an innovative coupled experimental framework integrating dynamic-static cyclic loading(to simulate perforation impact)and acid erosion.Static uniaxial compression tests were performed on treated damaged shale samples,with microstructural characterization via X-ray diffraction(XRD)and scanning electron microscopy(SEM).Key findings include:(1)The damage factor(characterized by longitudinal wave velocity)showed a significant positive correlation with acid concentration;(2)Combined damage(impact+acidization)caused far more severe mechanical deterioration than single damage modes—for instance,samples under combined damage with 20%hydrochloric acid exhibited a strength reduction to 158.97 MPa,with sharp decreases in peak strength and elastic modulus;(3)Damage reduced total energy and elastic strain energy of samples while increasing dissipated energy proportion,leading to more developed internal fractures and severe failure in combined damage samples;(4)Acidization promoted sample fragmentation into smaller debris,resulting in significantly higher fractal dimensions of acidized shale than other damage types under the same acid concentration;(5)XRD and SEM analyses confirmed that high-concentration acid erosion reduced shale carbonate content,and the synergy of mechanical pre-damage and chemical dissolution in combined damage accelerated acid-rock reactions,significantly increasing micro-interfacial pores and degrading shale structural integrity.This study’s innovation lies in establishing a coupled experimental framework that reproduces the actual“perforation-acidization”sequence,quantitatively revealing the synergistic degradation mechanism of shale mechanical properties under combined damage—providing a novel theoretical basis for optimizing shale reservoir stimulation parameters.
基金the financial support by the Major Science and Technology Achievement Transformation Project in Heilongjiang Province(No.ZC2023SH0075)the National Natural Science Foundation of China(Nos.52425401,U2441255,52474377,and 52371015)+1 种基金the Young Elite Scientists Sponsorship·Program by CAST(No.2021QNRC001)the Henan Provincial Key Research and Development&Promotion Special Program(No.251111231400)。
文摘The microstructure of high Nb-TiAl alloys was optimized by the addition of a small amount of Ta elements to further improve their properties.A series of Ti46Al1.5Cr8Nb-xTa(x=0.2,0.4,0.6,0.8,1.0,at.%)alloys were prepared by vacuum arc melting.The microstructure,mechanical properties,and related influencing mechanisms were systematically investigated.The results indicate that the solidification microstructure of the Ti46Al1.5Cr8Nb-xTa alloys comprises theγ-TiAl phase,α_(2)-Ti_(3)Al phase,and B2 phase.As the Ta content increases from 0.2 at.%to 1.0 at.%,the content ofα_(2)phase and B2 phase increases,while theγphase content decreases.Among them,the B2 phase shows the most pronounced change,being significantly refined,with its content increasing from 12.49%to 21.91%.In addition,the average size of the lamellar colony decreases from 160.65 to 94.44μm.The addition of the Ta element shifts the solidification path toward lower aluminum concentrations,leading to changes in phase content.The tantalum-induced increase in the B2 phase and enhanced supercooling at the solidification front provide the basis for lamellar colony refinement.Compressive testing at room temperature reveals that the Ti46 Al1.5 Cr8 Nb0.4 Ta alloy exhibits optimal compressive properties,achieving a compressive strength of 2,434 MPa and a compressive strain of 33.1%.The improvement of its properties is attributed to a combination of lamellar colony refinement,solid solution strengthening resulting from the incorporation of Ta element,and a reduction in the c/a of theγphase.
基金funded by the National Natural Science Foundation of China (52061020).
文摘Quantitative analysis of aluminum-silicon(Al-Si)alloy microstructure is crucial for evaluating and controlling alloy performance.Conventional analysis methods rely on manual segmentation,which is inefficient and subjective,while fully supervised deep learning approaches require extensive and expensive pixel-level annotated data.Furthermore,existing semi-supervised methods still face challenges in handling the adhesion of adjacent primary silicon particles and effectively utilizing consistency in unlabeled data.To address these issues,this paper proposes a novel semi-supervised framework for Al-Si alloy microstructure image segmentation.First,we introduce a Rotational Uncertainty Correction Strategy(RUCS).This strategy employs multi-angle rotational perturbations andMonte Carlo sampling to assess prediction consistency,generating a pixel-wise confidence weight map.By integrating this map into the loss function,the model dynamically focuses on high-confidence regions,thereby improving generalization ability while reducing manual annotation pressure.Second,we design a Boundary EnhancementModule(BEM)to strengthen boundary feature extraction through erosion difference and multi-scale dilated convolutions.This module guides the model to focus on the boundary regions of adjacent particles,effectively resolving particle adhesion and improving segmentation accuracy.Systematic experiments were conducted on the Aluminum-Silicon Alloy Microstructure Dataset(ASAD).Results indicate that the proposed method performs exceptionally well with scarce labeled data.Specifically,using only 5%labeled data,our method improves the Jaccard index and Adjusted Rand Index(ARI)by 2.84 and 1.57 percentage points,respectively,and reduces the Variation of Information(VI)by 8.65 compared to stateof-the-art semi-supervised models,approaching the performance levels of 10%labeled data.These results demonstrate that the proposed method significantly enhances the accuracy and robustness of quantitative microstructure analysis while reducing annotation costs.
基金financially and technically supported by the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact,Beijing Institute of Technology,China(No.WDZC2024-1)。
文摘Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic rolled SF-7055 Al alloy is elongated to form a fiber texture.Numerous proliferating dislocations in the microstructure accumulate into dislocation walls and cells,and eventually form subgrains.These subgrain boundaries divide the original grain,thereby reducing the grain size.Under severe deformation conditions,they even enable the formation of nanograins.Meanwhile,the Cu-rich precipitates in the matrix are also broken and refined under the action of large rolling stress.In the process of cryogenic rolling,the tensile strength and hardness of SF-7055 Al alloy gradually increase,while the plasticity decreases.Moreover,the fracture morphology of cryogenic rolled SF-7055 Al alloy gradually transforms to the ductile and quasi-cleavage hybrid fracture characteristics with increased reduction.
基金financially supported by the Natural Science Foundation of Liaoning Province of China(2022-MS-109)the Key Research and Development Program of Liaoning Province(2023JH2/101800045)the Ministry of Science and Technology of the Peoples Republic of China(ZZ2021006).
文摘The Cu-12Fe alloy has attracted significant attention due to its excellent electrical conductivity and electromagnetic shielding capability,high strength,cost-effectiveness,and recyclability.In the present work,the Cu-12Fe alloy strip with the thickness of 2.4 mm was successfully produced by twin-roll strip casting.The microstructure and properties of the Cu-12Fe alloy were tailored by cold rolling and aging treatment.The tensile strength of the as-cast strip is approximately 328 MPa and its elongation is 25%.The Fe phase randomly dispersed in the matrix,and the average size of Fe-rich phase is 2μm.Besides,enrichment of Fe phase is observed in the central layer of the strip,results in the formation of the“sandwich structure”.Moreover,the as-cast strip of Cu-12Fe was directly cold-rolled from 2.4 to 0.12 mm.The directly cold-rolled sample after aging at 450℃for 16 h(ProcessⅠ)shows excellent electrical conductivity of 69.5%IACS,the tensile strength and elongation are 513 MPa and 3.8%,the saturation magnetic flux density is 20.1 emu·g^(-1),and the coercive force is 25.2 Oe.In ProcessⅡ,the as-cast strip firstly cold-rolled to 1.2 mm,then aged at 500℃for 1.5 h,followed by cold rolling to 0.12 mm,finally aged at 450℃for 16 h.The sample after ProcessⅡshows the electrical conductivity of 66.3%IACS,the tensile strength of 533 MPa,an elongation of 3.5%,saturation magnetic flux density of 21.4 emu·g^(-1),and the coercive force of 22.3 Oe.
基金financially supported by the National Science Fund for Distinguished Young Scholars,China(No.52025041)the National Natural Science Foundation of China(Nos.52450003,U2341267,and 52174294)+1 种基金the National Postdoctoral Program for Innovative Talents,China(No.BX20240437)the Fundamental Research Funds for the Central Universities,China(Nos.FRF-IDRY-23-037 and FRF-TP-20-02C2)。
文摘The rapid advancements in computer vision(CV)technology have transformed the traditional approaches to material microstructure analysis.This review outlines the history of CV and explores the applications of deep-learning(DL)-driven CV in four key areas of materials science:microstructure-based performance prediction,microstructure information generation,microstructure defect detection,and crystal structure-based property prediction.The CV has significantly reduced the cost of traditional experimental methods used in material performance prediction.Moreover,recent progress made in generating microstructure images and detecting microstructural defects using CV has led to increased efficiency and reliability in material performance assessments.The DL-driven CV models can accelerate the design of new materials with optimized performance by integrating predictions based on both crystal and microstructural data,thereby allowing for the discovery and innovation of next-generation materials.Finally,the review provides insights into the rapid interdisciplinary developments in the field of materials science and future prospects.
基金supported by the Jiangxi Provincial Natural Science Foundation of China(Grant number 20224BAB204049)the Fund Project of Jiangxi Provincial Department of Education(Grant number GJJ2200602)the National Natural Science Foundation of China(Grant number 52205194)。
文摘The laser-clad Fe45 alloy coating inherently comprises multiple crystalline phases,resulting in a heterogeneous microstructural distribution that influences its performance.In this study,the rare earth yttria(Y_(2)O_(3))was employed to modify laser-clad Fe45 alloy coatings,and the effects of Y_(2)O_(3) addition on their microstructure,microhardness,and tribological properties were investigated.As the Y_(2)O_(3) content increases from 0%to 0.3wt.%,the dominant microstructure transforms from columnar crystals to fine cellular and equiaxed crystals.The modified coating with 0.3wt.%Y_(2)O_(3) achieves a surface hardness of 568 HV_(0.3)and a wear volume of 1,735.41 um~3,representing a 14.06%increase in hardness and a 51.16%reduction in wear volume compared to the undoped coating.Further increasing the Y_(2)O_(3) content from 0.3wt.%to 0.9wt.%gradually leads to the emergence of a coarser feather-like microstructure,characterized by a dendritic framework with inter-dendritic equiaxed crystals.Concurrently,both the hardness and wear resistance of the coating decrease.Nevertheless,all Y_(2)O_(3)-modified coatings surpass the undoped Fe45 coating in both hardness and wear resistance.Appropriate Y_(2)O_(3) doping effectively refines the Fe45 alloy coating's microstru cture and induces lattice distortion,thereby enhancing its hardness and wear resistance.
