Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durabili...Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application.展开更多
Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipmen...Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipment manufacturing,and electronic information.This review provides a comprehensive summary of the progress of AM technology in WC−Co cemented carbides.The fundamental principles and classification of AM techniques are introduced,followed by a categorization and evaluation of the AM techniques for WC−Co cemented carbides.These techniques are classified as either direct AM technology(DAM)or indirect AM technology(IDAM),depending on their inclusion of post-processes like de-binding and sintering.Through an analysis of microstructure features,the most suitable AM route for WC−Co cemented carbide products with controllable microstructure is identified as the indirect AM technology,such as binder jet printing(BJP),which integrates AM with conventional powder metallurgy.展开更多
Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing addit...Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.展开更多
Additive manufacturing(AM),with its high flexibility,cost-effectiveness,and customization,significantly accelerates the advancement of nanogenerators,contributing to sustainable energy solutions and the Internet of Th...Additive manufacturing(AM),with its high flexibility,cost-effectiveness,and customization,significantly accelerates the advancement of nanogenerators,contributing to sustainable energy solutions and the Internet of Things.In this review,an in-depth analysis of AM for piezoelectric and triboelectric nanogenerators is presented from the perspectives of fundamental mechanisms,recent advancements,and future prospects.It highlights AM-enabled advantages of versatility across materials,structural topology optimization,microstructure design,and integrated printing,which enhance critical performance indicators of nanogenerators,such as surface charge density and piezoelectric constant,thereby improving device performance compared to conventional fabrication.Common AM techniques for nanogenerators,including fused deposition modeling,direct ink writing,stereolithography,and digital light processing,are systematically examined in terms of their working principles,improved metrics(output voltage/current,power density),theoretical explanation,and application scopes.Hierarchical relationships connecting AM technologies with performance optimization and applications of nanogenerators are elucidated,providing a solid foundation for advancements in energy harvesting,self-powered sensors,wearable devices,and human-machine interaction.Furthermore,the challenges related to fabrication quality,cross-scale manufacturing,processing efficiency,and industrial deployment are critically discussed.Finally,the future prospects of AM for nanogenerators are explored,aiming to foster continuous progress and innovation in this field.展开更多
Achieving simultaneous enhancement of crystallinity and optimal domain size remains a fundamental challenge in organic photovoltaics(OPVs),where conventional crystallization strategies often trigger excessive aggregat...Achieving simultaneous enhancement of crystallinity and optimal domain size remains a fundamental challenge in organic photovoltaics(OPVs),where conventional crystallization strategies often trigger excessive aggregation of small-molecule acceptors.This work pioneers a kinetic paradigm for resolving the crystallinity-domain size trade-off in organic photovoltaics through dual-additive-guided stepwise crystallization.By strategically pairing 1,2-dichlorobenzene(o-DCB,low binding energy to Y6)and 1-fluoronaphthalene(FN,high binding energy),we achieve temporally decoupled crystallization control:o-DCB first mediates donor-acceptor co-crystallization during film formation,constructing a metastable network,whereupon FN induces confined Y6 crystallization within this framework during thermal annealing,refining nanostructure without over-aggregation.Morphology studies reveal that this synergy enhances crystallinity of(100)diffraction peaks by 21%–10%versus single-additive controls(o-DCB/FN alone),while maintaining optimal domain size.These morphological advantages yield balanced carrier transport(μh/μe=1.23),near-unity exciton dissociation(98.53%),and a champion power conversion efficiency(PCE)of 18.08%for PM6:Y6,significantly surpassing single-additive devices(o-DCB:17.20%;FN:17.53%).Crucially,the dual-additive strategy demonstrates universal applicability across diverse active layer systems,achieving an outstanding PCE of 19.27%in PM6:L8-BO-based devices,thereby establishing a general framework for morphology control in high-efficiency OPVs.展开更多
Functionally graded cellular structures(FGCSs)have a multitude of applications to a wide range of industries.Utilising the ever-progressing technology of additive manufacturing(AM),FGCSs can be applied to control mate...Functionally graded cellular structures(FGCSs)have a multitude of applications to a wide range of industries.Utilising the ever-progressing technology of additive manufacturing(AM),FGCSs can be applied to control material grading and achieve the desired mechanical properties.The current study explores the design and optimisation of FGCSs for AM,with a focus on improving the compression and impact performance of below knee(BK)prosthetic limbs made of thermoplastic polyurethane(TPU).A multiscale research methodology integrating topology optimization(TO),finite element analysis(FEA),and design of experiments(Do E)was adopted to optimise lattice structures in terms of stiffness and lightweight properties.Two-unit cell designs were considered in the study:Schwarz P gyroid and body-centered cubic(BCC).Response surface methodology(RSM)was implemented to analyse the effect of minimum and maximum cell wall thickness,cell size,and unit cell type on the mechanical performance of TPU FGCS structures.The results indicated that a Schwarz P FGCS structure with cell size,minimum and maximum cell wall thickness of 6,0.9 and 2.8 mm,respectively,could be optimal for a compromise between performance and weight.In this optimized case,stiffness and volume fraction values of 684 N/mm and 0.64 were obtained,respectively.The study also presents a proof-of-concept design for a BK prosthetic damper,highlighting the potential of FGCSs to enhance patient comfort,reduce manufacturing costs,and enable personalised designs through 3D scanning and AM.The obtained results could be a step forward towards the incorporation of AM technologies in prosthetics,offering a pathway to lightweight,cost-effective,and functionally tailored solutions.展开更多
The accelerated shift toward high efficiency and sustainability of the iron and steel is driving the advancement of green,low-carbon and high-quality carbon-containing refractories used for ladles.It is undoubtedly a ...The accelerated shift toward high efficiency and sustainability of the iron and steel is driving the advancement of green,low-carbon and high-quality carbon-containing refractories used for ladles.It is undoubtedly a significant challenge,since the addition of graphite enables refractories to possess superior thermal shock resistance and slag corrosion resistance.To develop low carbon-containing refractories with excellent properties,researchers over the past decades have endeavored to seek additives which can mitigate the adverse effects associated with the decrease in carbon in refractories.These additives can promote the occurrence of various mechanisms about toughening,which depends on inherent properties of additives or reacting with refractories to in situ form different ceramic phases,thereby responding the challenge of low-carbonization in refractories.The latest advances in additives used for low carbon-containing refractories from metal/alloys,oxide,non-oxide and composite powders four aspects were comprehensively overviewed in this review.Oxide additives exhibit a moderate effect on improving thermal shock resistance of refractories but show limited efficacy in improving oxidation resistance.In contrast,non-oxide additives demonstrate remarkable advantages in enhancing both oxidation and slag corrosion resistance.Composite powders combine the advantageous properties of their individual components.These additives often require combination with antioxidants such as Al,Si,or B4C not only to reduce costs but also to achieve optimal properties.Furthermore,future perspectives of these additives are discussed,with the aim of providing useful insights for the continuous progress and practical application of low carbon-containing refractories.展开更多
Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes canno...Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes cannot achieve high active material loading and efficient ion/electron transport simultaneously.By contrast,three-dimensional(3D)structures have attracted increasing interest because of their capacity to enhance active material utilization,shorten ion and electron transport pathways,reduce interfacial impedance,and provide spatial accommodation for volume expansion.Additive manufacturing(AM)technology effectively fabricates energy-storage materials with 3D structures by accurately constructing complex 3D structures via layer-by-layer deposition.Recent studies have employed AM to construct ordered 3D electrodes that can optimize ion/electron transport,regulate electric field distribution,or improve the electrode-electrolyte interface,thereby contributing to enhanced kinetic performance and cycling stability.This review systematically summarizes the applications of several AM technologies in the fabrication of energy storage materials and analyzes their respective advantages and limitations.Subsequently,the advantages of AM technology in the fabrication of energy storage materials and several major optimization strategies are comprehensively discussed.Finally,the major challenges and potential applications of AM technology in energy storage material optimization are discussed.展开更多
Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-ins...Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-inspired lattice structures feature a square-grid 2D lattice with double diagonal bracings and are additively manufactured via digital light processing(DLP).The collapse strength and energy absorption capacity of sea sponge lattice structures are evaluated under various impact conditions and are compared to those of their constituent square-grid and double diagonal lattices.This study demonstrates that sea sponge lattices can achieve an 11-fold increase in energy absorption compared to the square-grid lattice,due to the stabilizing effect of the double diagonal bracings prompting the structure to collapse layer-bylayer under impact.By adjusting the thickness ratio in the sea sponge lattice,up to 76.7%increment in energy absorption is attained.It is also shown that sea-sponge lattices outperform well-established energy-absorbing materials of equal weight,such as hexagonal honeycombs,confirming their significant potential for impact mitigation.Additionally,this research highlights the enhancements in energy absorption achieved by adding a small amount(0.015 phr)of Multi-Walled Carbon Nanotubes(MWCNTs)to the photocurable resin,thus unlocking new possibilities for the design of innovative lightweight structures with multifunctional attributes.展开更多
At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass components.In this study,multi-laye...At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass components.In this study,multi-layer multi-pass FRAM-deposited alumin-um alloy samples were successfully prepared using a non-shoulder tool head.The material flow behavior and microstructure of the over-lapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum alloys.The results showed that a mechanical interlocking structure was formed between the adjacent layers and the adja-cent passes in the overlapped center area.Repeated friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone,which made the recrystallization degree in the left and right edge zones of the over-lapped zone the highest,followed by the overlapped center zone and the non-overlapped zone.The tensile strength of the overlapped zone exceeded 90%of that of the single-pass deposition sample.It is proved that although there are uneven grooves on the surface of the over-lapping area during multi-layer and multi-pass deposition,they can be filled by the flow of materials during the deposition of the next lay-er,thus ensuring the dense microstructure and excellent mechanical properties of the overlapping area.The multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.展开更多
Laser additive manufacturing(LAM)has been widely used in high-end manufacturing fields such as aerospace,nuclear power,and shipbuilding.However,it is a grand challenge for direct and continuous observation of complex ...Laser additive manufacturing(LAM)has been widely used in high-end manufacturing fields such as aerospace,nuclear power,and shipbuilding.However,it is a grand challenge for direct and continuous observation of complex laser-matter interaction,melt flow,and defect formation during LAM due to extremely large temperature gradient,fast cooling rate,and small time(millisecond)and space(micron)scales.The emergence of synchrotron radiation provides a feasible approach for in situ observation of the LAM process.This paper outlines the current development in real-time characterization of LAM by synchrotron radiation,including laser-matter interaction,molten pool evolution,solidification structure evolution,and defects formation and elimination.Furthermore,the future development direction and application-oriented research are also discussed.展开更多
AA6061 is a widely used aluminum alloy with significant applications in the aerospace and automotive industries.Despite its popularity,the utilization of additively manufactured AA6061 through the laser powder bed fus...AA6061 is a widely used aluminum alloy with significant applications in the aerospace and automotive industries.Despite its popularity,the utilization of additively manufactured AA6061 through the laser powder bed fusion(LPBF)process has been hindered by the pronounced formation of pores and cracks during rapid solidification.This study quantitatively investigated defects,including pores and cracks,and microstructures,including texture,grain size,subgrain structure,and precipitates,of LPBF-manufactured AA6061 across a broad spectrum of laser power and speed combinations.A high relative density of more than 99%was achieved with a low-power and low-speed condition,specifically 200 W and 100 mm s−1,with minimal cracks.Large pores,akin to or exceeding melt pool dimensions,emerged under either low or high energy densities,driven by the lack of fusion and vaporization/denudation mechanisms,re-spectively.Solidification cracks,confirmed by the fractography,were propagated along grain boundaries and are highly dependent on laser scanning speed.Elevated power and speed exhibited finer grain size with refined subgrain cellular structures and increased precipitates at interdendritic regions.The cooling rate and thermal gradient estimated from thermal analytical solutions explain the microstructures’char-acteristics.Nano-sized Si-Fe-Mg enriched precipitates are confirmed in both as-built and heat-treated conditions,whereas T6 heat treatment promotes a uniform distribution with coarsening of those precipi-tates.The low-power and low-speed conditions demonstrated the highest yield strength,consistent with defect levels.A minimum of 102.3%increase in yield strength with reduced ductility was observed after heat treatment for all examined conditions.This work sheds light on printing parameters to mitigate the formation of pores and cracks in additively manufactured AA6061,proposing a process window for op-timized fabrication and highlighting the potential for enhanced material properties and reduced defects through process control.展开更多
SiC is a wave-absorbing material with good dielectric properties,high-temperature resistance,and corrosion resistance,which has great potential for development in the field of high-temperature wave-absorbing.However,S...SiC is a wave-absorbing material with good dielectric properties,high-temperature resistance,and corrosion resistance,which has great potential for development in the field of high-temperature wave-absorbing.However,SiC is limited by its low impedance-matching performance and single wave-absorbing mechanism.Therefore,compatible metamaterial technologies are required to enhance its wave-absorbing performance further.The electromagnetic wave(EMW)absorbing metamaterials can realize perfect absorption of EMWs in specific frequency bands and precise regulation of EMW phase,propagation mode,and absorption frequency bands through structural changes.However,the traditional molding methods for manufacturing complex geometric shapes require expensive molds,involve process complexity,and have poor molding accuracy and other limitations.Therefore,additive manufacturing(AM)technology,through material layered stacking to achieve the processing of materials,is a comprehensive multidisciplinary advanced manufacturing technology and has become the core technology for manufacturing metamaterials.This review introduces the principles and applications of different AM technologies for SiC and related materials,discusses the current status and development trends of various AM technologies for fabricating silicon-carbon-based wave-absorbing metamaterials,summarizes the limitations and technological shortcomings of existing AM technologies for fabricating silicon-carbon-based wave-absorbing metamaterials,and provides an outlook for the future development of related AM technologies.展开更多
1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-...1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-sized particles(5-50μm)to fabricate coatings[1-3].CS has been extensively used in a variety of coating applications,such as aerospace,automotive,energy,medical,marine,and others,to provide protection against high temperatures,corrosion,erosion,oxidation,and chemicals[4,5].Nowadays,the technical interest in CS is twofold:(i)as a repair process for damaged components,and(ii)as a solid-state additive manufacturing process.Compared to other fusion-based additive manufacturing(AM)technologies,Cold Spray Additive Manufacturing(CSAM)is a new member of the AM family that can enable the fabrication of deposits without undergoing melting.The chemical composition has been largely preserved from the powder to the deposit due to the minimal oxidation.The significant advantages of CSAM over other additive manufacturing processes include a high production rate,unlimited deposition size,high flexibility,and suitability for repairing damaged parts.展开更多
Many strategies have been proposed to produce arenes from lignin as liquid fuel additives.However,the development of these methods is limited by the low yield of products,low atom utilization,and inefficient lignin de...Many strategies have been proposed to produce arenes from lignin as liquid fuel additives.However,the development of these methods is limited by the low yield of products,low atom utilization,and inefficient lignin depolymerization.Herein,we develop an energy-efficient synthetic method for the production of high-carbon-number arenes from sustainable lignin with a total yield of 23.1 wt%.Particularly,high carbon number arenes are obtained by fully utilizing the formaldehyde stabilizing additive and the methoxy group in lignin.The process begins with the reductive depolymerization of formaldehyde-stabilized lignin,followed by transmethylation between lignin monomers over Au/Nb_(2)O_(5) catalyst,and the Ru/Nb2O5-catalyzed hydrodeoxygenation.This work demonstrates the potential of value-added arenes production directly from lignin.展开更多
Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency...Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency of FRAM,which depends only on friction to generate heat,is low,and the thermal-accumulation effect of the deposition process must be addressed.An FRAM heat-balance-control method that combines plasma-arc preheating and instant water cooling(PC-FRAM)is devised in this study,and a temperature field featuring rapidly increasing and decreasing temperature is constructed around the tool head.Additionally,2195-T87 Al-Li alloy is used as the feed material,and the effects of heating and cooling rates on the microstructure and mechanical properties are investigated.The results show that water cooling significantly improves heat accumulation during the deposition process.The cooling rate increases by 11.7 times,and the high-temperature residence time decreases by more than 50%.The grain size of the PC-FRAM sample is the smallest,i.e.,3.77±1.03μm,its dislocation density is the highest,and the number density of precipitates is the highest,the size of precipitates is the smallest,which shows the best precipitation-strengthening effect.The hardness test results are consistent with the precipitation distribution.The ultimate tensile strength,yield strength and elongation of the PC-FRAM samples are the highest(351±15.6 MPa,251.3±15.8 MPa and 16.25%±1.25%,respectively)among the samples investigated.The preheating and water-cooling-assisted deposition simultaneously increases the tensile strength and elongation of the deposited samples.The combination of preheating and instant cooling improves the deposition efficiency of FRAM and weakens the thermal-softening effect.展开更多
In this review,we propose a comprehensive overview of additive manufacturing(AM)technologies and design possibilities in manufacturing metamaterials for various applications in the biomedical field,of which many are i...In this review,we propose a comprehensive overview of additive manufacturing(AM)technologies and design possibilities in manufacturing metamaterials for various applications in the biomedical field,of which many are inspired by nature itself.It describes how new AM technologies(e.g.continuous liquid interface production and multiphoton polymerization,etc)and recent developments in more mature AM technologies(e.g.powder bed fusion,stereolithography,and extrusion-based bioprinting(EBB),etc)lead to more precise,efficient,and personalized biomedical components.EBB is a revolutionary topic creating intricate models with remarkable mechanical compatibility of metamaterials,for instance,stress elimination for tissue engineering and regenerative medicine,negative or zero Poisson’s ratio.By exploiting the designs of porous structures(e.g.truss,triply periodic minimal surface,plant/animal-inspired,and functionally graded lattices,etc),AM-made bioactive bone implants,artificial tissues,and organs are made for tissue replacement.The material palette of the AM metamaterials has high diversity nowadays,ranging from alloys and metals(e.g.cobalt-chromium alloys and titanium,etc)to polymers(e.g.biodegradable polycaprolactone and polymethyl methacrylate,etc),which could be even integrated within bioactive ceramics.These advancements are driving the progress of the biomedical field,improving human health and quality of life.展开更多
In wire arc additive manufacturing(WAAM),a trade-off exists among deposition efficiency,microstructure,and mechanical properties.Addressing this challenge,this work proposes an innovative multi-objective optimization ...In wire arc additive manufacturing(WAAM),a trade-off exists among deposition efficiency,microstructure,and mechanical properties.Addressing this challenge,this work proposes an innovative multi-objective optimization framework tailored for WAAM of AZ31 magnesium alloy components,which integrates deposition efficiency and microstructure as coupled objectives and is resolved through the NSGA-Ⅱ algorithm.The proposed framework employs quadratic regression to correlate process parameters with deposition efficiency through geometric morphology mediation,while addressing uncertainties in WAAM by integrating theoretical insights with data-driven stacked ensemble learning for grain size prediction,establishing the hybrid physics-informed data method for WAAM microstructure prediction.The optimized process achieved a deposition rate of 6257 mm3/min,with effective width and average layer height maintained at 10.1 mm and 4.13 mm,respectively.Microstructural optimization produced a fine,uniform,fully equiaxed grain structure with an average grain size of 38μm.These findings underscore the significant industrial potential of intelligent optimization strategies in WAAM for manufacturing lightweight,high-performance components in aerospace and transportation sectors.展开更多
Additive manufacturing(AM)technology has demonstrated significant potential in the green,lightweight,and functional development of metal materials,offering greater freedom and flexibility in the manufacturing process....Additive manufacturing(AM)technology has demonstrated significant potential in the green,lightweight,and functional development of metal materials,offering greater freedom and flexibility in the manufacturing process.However,the microstructural heterogeneity and mechanical property anisotropy of nickel-based superalloys along the build direction,stemming from thermal cycling,limit their widespread application in the aerospace industry.The proposed hybrid manufacturing process introduces external energy fields(thermal,ultrasonic,magnetic fields)into the forming processes,offering an innovative pathway to overcome the limitations of AM superalloys.This paper systematically discusses the influence of energy fields on the AM process of nickel-based superalloys,focusing on key issues such as cracking,porosity,microstructural heterogeneity,and mechanical property.Various energy fields modulate the melt pool dynamics and solidification process through distinct mechanisms.However,there remain several unresolved challenges and controversies regarding their mechanisms,particularly concerning the microstructural evolution under the synergistic effects of multiple energy fields.To address this issue,current studies predominantly focus on experimental validation,with a lack of unified theoretical models and numerical simulations,which limits the further development of energy field optimization strategies.Accordingly,the roles and advantages of various energy fields in AM of nickel-based superalloys are summarized.And engineering challenges are highlighted,such as multi-field synergistic control strategies,quantitative prediction models for microstructure-property,and energy field optimization methods for practical applications.Finally,the future trends of energy field-assisted AM for high-performance superalloys are discussed,with an outlook on its potential applications in re-manufacturing technologies and integrated equipment.展开更多
Aqueous-electrolyte-based zinc-ion batteries(ZIBs),which have significant advantages over other batteries,including low cost,high safety,high ionic conductivity,and a natural abundance of zinc,have been regarded as a ...Aqueous-electrolyte-based zinc-ion batteries(ZIBs),which have significant advantages over other batteries,including low cost,high safety,high ionic conductivity,and a natural abundance of zinc,have been regarded as a potential alternative to lithium-ion batteries(LIBs).ZIBs still face some critical challenges,however,especially for building a reversible zinc anode.To address the reversibility of zinc anode,great efforts have been made on intrinsic anode engineering and anode interface modification.Less attention has been devoted to the electrolyte additives,however,which could not only significantly improve the reversibility of zinc anode,but also determine the viability and overall performance of ZIBs.This review aims to provide an overview of the two main functions of electrolyte additives,followed by details on six reasons why additives might improve the performance of ZIBs from the perspectives of creating new layers and regulating current plating/stripping processes.Furthermore,the remaining difficulties and potential directions for additives in aqueous ZIBs are also highlighted.展开更多
基金National MCF Energy R&D Program(2024YFE03260300)。
文摘Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application.
基金supported by Major Science and Technology Projects in Fujian Province,China(No.2023HZ021005)State Key Laboratory of Powder Metallurgy,Central South University,ChinaFujian Key Laboratory of Rare-earth Functional Materials,China。
文摘Additive manufacturing(AM)technology has emerged as a viable solution for manufacturing complexshaped WC−Co cemented carbide products,thereby expanding their applications in industries such as resource mining,equipment manufacturing,and electronic information.This review provides a comprehensive summary of the progress of AM technology in WC−Co cemented carbides.The fundamental principles and classification of AM techniques are introduced,followed by a categorization and evaluation of the AM techniques for WC−Co cemented carbides.These techniques are classified as either direct AM technology(DAM)or indirect AM technology(IDAM),depending on their inclusion of post-processes like de-binding and sintering.Through an analysis of microstructure features,the most suitable AM route for WC−Co cemented carbide products with controllable microstructure is identified as the indirect AM technology,such as binder jet printing(BJP),which integrates AM with conventional powder metallurgy.
基金National Key Research and Development Program of China(2022YFB4600902)Shandong Provincial Science Foundation for Outstanding Young Scholars(ZR2024YQ020)。
文摘Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.
基金support from the Research Committee of The Hong Kong Polytechnic University(Project codes:RMJK and 4-ZZSJ)supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.PolyU15212523).
文摘Additive manufacturing(AM),with its high flexibility,cost-effectiveness,and customization,significantly accelerates the advancement of nanogenerators,contributing to sustainable energy solutions and the Internet of Things.In this review,an in-depth analysis of AM for piezoelectric and triboelectric nanogenerators is presented from the perspectives of fundamental mechanisms,recent advancements,and future prospects.It highlights AM-enabled advantages of versatility across materials,structural topology optimization,microstructure design,and integrated printing,which enhance critical performance indicators of nanogenerators,such as surface charge density and piezoelectric constant,thereby improving device performance compared to conventional fabrication.Common AM techniques for nanogenerators,including fused deposition modeling,direct ink writing,stereolithography,and digital light processing,are systematically examined in terms of their working principles,improved metrics(output voltage/current,power density),theoretical explanation,and application scopes.Hierarchical relationships connecting AM technologies with performance optimization and applications of nanogenerators are elucidated,providing a solid foundation for advancements in energy harvesting,self-powered sensors,wearable devices,and human-machine interaction.Furthermore,the challenges related to fabrication quality,cross-scale manufacturing,processing efficiency,and industrial deployment are critically discussed.Finally,the future prospects of AM for nanogenerators are explored,aiming to foster continuous progress and innovation in this field.
基金supported by the Shaanxi Provincial High level Talent Introduction Project(5113220044)the Shaanxi Outstanding Youth Project(2023-JC-JQ-33)+8 种基金the Youth Science and Technology Talent Promotion Project of Jiangsu Association for Science and Technology(TJ-2022-088)the Project funded by China Postdoctoral Science Foundation(2023TQ0273,2023TQ0274,2023M742833)the NationalNatural Science Foundation of China(62304181)the Natural Science Basic Research Program of Shaanxi(2023-JC-QN-0726,2025JC-YBQN-469)the GuangdongBasic and Applied Basic Research Foundation(2022A1515110286,2024A1515012538)the Basic Research Programs of Taicang(TC2024JC04)the Suzhou Science and Technology Development Plan Innovation Leading Talent Project(ZXL2023183)the Fundamental Research Funds for the Central Universities(G2022KY05108,G2024KY0605,G2023KY0601)and the Aeronautical Science Foundation of China(2018ZD53047).
文摘Achieving simultaneous enhancement of crystallinity and optimal domain size remains a fundamental challenge in organic photovoltaics(OPVs),where conventional crystallization strategies often trigger excessive aggregation of small-molecule acceptors.This work pioneers a kinetic paradigm for resolving the crystallinity-domain size trade-off in organic photovoltaics through dual-additive-guided stepwise crystallization.By strategically pairing 1,2-dichlorobenzene(o-DCB,low binding energy to Y6)and 1-fluoronaphthalene(FN,high binding energy),we achieve temporally decoupled crystallization control:o-DCB first mediates donor-acceptor co-crystallization during film formation,constructing a metastable network,whereupon FN induces confined Y6 crystallization within this framework during thermal annealing,refining nanostructure without over-aggregation.Morphology studies reveal that this synergy enhances crystallinity of(100)diffraction peaks by 21%–10%versus single-additive controls(o-DCB/FN alone),while maintaining optimal domain size.These morphological advantages yield balanced carrier transport(μh/μe=1.23),near-unity exciton dissociation(98.53%),and a champion power conversion efficiency(PCE)of 18.08%for PM6:Y6,significantly surpassing single-additive devices(o-DCB:17.20%;FN:17.53%).Crucially,the dual-additive strategy demonstrates universal applicability across diverse active layer systems,achieving an outstanding PCE of 19.27%in PM6:L8-BO-based devices,thereby establishing a general framework for morphology control in high-efficiency OPVs.
基金financially supported and funded by the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)(No.IMSIU-DDRSP2503)。
文摘Functionally graded cellular structures(FGCSs)have a multitude of applications to a wide range of industries.Utilising the ever-progressing technology of additive manufacturing(AM),FGCSs can be applied to control material grading and achieve the desired mechanical properties.The current study explores the design and optimisation of FGCSs for AM,with a focus on improving the compression and impact performance of below knee(BK)prosthetic limbs made of thermoplastic polyurethane(TPU).A multiscale research methodology integrating topology optimization(TO),finite element analysis(FEA),and design of experiments(Do E)was adopted to optimise lattice structures in terms of stiffness and lightweight properties.Two-unit cell designs were considered in the study:Schwarz P gyroid and body-centered cubic(BCC).Response surface methodology(RSM)was implemented to analyse the effect of minimum and maximum cell wall thickness,cell size,and unit cell type on the mechanical performance of TPU FGCS structures.The results indicated that a Schwarz P FGCS structure with cell size,minimum and maximum cell wall thickness of 6,0.9 and 2.8 mm,respectively,could be optimal for a compromise between performance and weight.In this optimized case,stiffness and volume fraction values of 684 N/mm and 0.64 were obtained,respectively.The study also presents a proof-of-concept design for a BK prosthetic damper,highlighting the potential of FGCSs to enhance patient comfort,reduce manufacturing costs,and enable personalised designs through 3D scanning and AM.The obtained results could be a step forward towards the incorporation of AM technologies in prosthetics,offering a pathway to lightweight,cost-effective,and functionally tailored solutions.
基金support of the National Natural Science Foundation of China(Grant/Project Nos.52272027,52372034 and 52502016)the China Postdoctoral Science Foundation(Grant No.2025T180025)Postdoctoral Fellowship Program(Grant No.GZC20252393).
文摘The accelerated shift toward high efficiency and sustainability of the iron and steel is driving the advancement of green,low-carbon and high-quality carbon-containing refractories used for ladles.It is undoubtedly a significant challenge,since the addition of graphite enables refractories to possess superior thermal shock resistance and slag corrosion resistance.To develop low carbon-containing refractories with excellent properties,researchers over the past decades have endeavored to seek additives which can mitigate the adverse effects associated with the decrease in carbon in refractories.These additives can promote the occurrence of various mechanisms about toughening,which depends on inherent properties of additives or reacting with refractories to in situ form different ceramic phases,thereby responding the challenge of low-carbonization in refractories.The latest advances in additives used for low carbon-containing refractories from metal/alloys,oxide,non-oxide and composite powders four aspects were comprehensively overviewed in this review.Oxide additives exhibit a moderate effect on improving thermal shock resistance of refractories but show limited efficacy in improving oxidation resistance.In contrast,non-oxide additives demonstrate remarkable advantages in enhancing both oxidation and slag corrosion resistance.Composite powders combine the advantageous properties of their individual components.These additives often require combination with antioxidants such as Al,Si,or B4C not only to reduce costs but also to achieve optimal properties.Furthermore,future perspectives of these additives are discussed,with the aim of providing useful insights for the continuous progress and practical application of low carbon-containing refractories.
基金support of the National Natural Science Foundation of China(No.52574411)Beijing Natural Science Foundation(No.2242043).
文摘Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes cannot achieve high active material loading and efficient ion/electron transport simultaneously.By contrast,three-dimensional(3D)structures have attracted increasing interest because of their capacity to enhance active material utilization,shorten ion and electron transport pathways,reduce interfacial impedance,and provide spatial accommodation for volume expansion.Additive manufacturing(AM)technology effectively fabricates energy-storage materials with 3D structures by accurately constructing complex 3D structures via layer-by-layer deposition.Recent studies have employed AM to construct ordered 3D electrodes that can optimize ion/electron transport,regulate electric field distribution,or improve the electrode-electrolyte interface,thereby contributing to enhanced kinetic performance and cycling stability.This review systematically summarizes the applications of several AM technologies in the fabrication of energy storage materials and analyzes their respective advantages and limitations.Subsequently,the advantages of AM technology in the fabrication of energy storage materials and several major optimization strategies are comprehensively discussed.Finally,the major challenges and potential applications of AM technology in energy storage material optimization are discussed.
基金supported by the Khalifa University of Science and Technology internal grants(Nos.2021-CIRA-109,2020-CIRA-007,and 2020-CIRA-024).
文摘Low-velocity impact tests are carried out to explore the energy absorption characteristics of bio-inspired lattices,mimicking the architecture of the marine sponge organism Euplectella aspergillum.These sea sponge-inspired lattice structures feature a square-grid 2D lattice with double diagonal bracings and are additively manufactured via digital light processing(DLP).The collapse strength and energy absorption capacity of sea sponge lattice structures are evaluated under various impact conditions and are compared to those of their constituent square-grid and double diagonal lattices.This study demonstrates that sea sponge lattices can achieve an 11-fold increase in energy absorption compared to the square-grid lattice,due to the stabilizing effect of the double diagonal bracings prompting the structure to collapse layer-bylayer under impact.By adjusting the thickness ratio in the sea sponge lattice,up to 76.7%increment in energy absorption is attained.It is also shown that sea-sponge lattices outperform well-established energy-absorbing materials of equal weight,such as hexagonal honeycombs,confirming their significant potential for impact mitigation.Additionally,this research highlights the enhancements in energy absorption achieved by adding a small amount(0.015 phr)of Multi-Walled Carbon Nanotubes(MWCNTs)to the photocurable resin,thus unlocking new possibilities for the design of innovative lightweight structures with multifunctional attributes.
基金supported by the National Key Research and Development Program of China(No.2022YFB3404700)the National Natural Science Foundation of China(Nos.52105313 and 52275299)+2 种基金the Research and Development Program of Beijing Municipal Education Commission,China(No.KM202210005036)the Natural Science Foundation of Chongqing,China(No.CSTB2023NSCQ-MSX0701)the National Defense Basic Research Projects of China(No.JCKY2022405C002).
文摘At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass components.In this study,multi-layer multi-pass FRAM-deposited alumin-um alloy samples were successfully prepared using a non-shoulder tool head.The material flow behavior and microstructure of the over-lapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum alloys.The results showed that a mechanical interlocking structure was formed between the adjacent layers and the adja-cent passes in the overlapped center area.Repeated friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone,which made the recrystallization degree in the left and right edge zones of the over-lapped zone the highest,followed by the overlapped center zone and the non-overlapped zone.The tensile strength of the overlapped zone exceeded 90%of that of the single-pass deposition sample.It is proved that although there are uneven grooves on the surface of the over-lapping area during multi-layer and multi-pass deposition,they can be filled by the flow of materials during the deposition of the next lay-er,thus ensuring the dense microstructure and excellent mechanical properties of the overlapping area.The multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.
基金supported by the National Natural Science Foundation of China-Distinguished Young Scholars(No.52325407)the National Natural Science Foundation of China-Key Program(No.52234010)the Open Research Fund of the State Key Laboratory of Rolling and Automation,Northeastern University(No.2022RALKFKT004).
文摘Laser additive manufacturing(LAM)has been widely used in high-end manufacturing fields such as aerospace,nuclear power,and shipbuilding.However,it is a grand challenge for direct and continuous observation of complex laser-matter interaction,melt flow,and defect formation during LAM due to extremely large temperature gradient,fast cooling rate,and small time(millisecond)and space(micron)scales.The emergence of synchrotron radiation provides a feasible approach for in situ observation of the LAM process.This paper outlines the current development in real-time characterization of LAM by synchrotron radiation,including laser-matter interaction,molten pool evolution,solidification structure evolution,and defects formation and elimination.Furthermore,the future development direction and application-oriented research are also discussed.
基金Savannah River National Laboratory(SRNL).SRNL is operated by Battelle Savannah River Alliance,LLC under Contract No 89303321CEM000080 for the US Department of Energy.
文摘AA6061 is a widely used aluminum alloy with significant applications in the aerospace and automotive industries.Despite its popularity,the utilization of additively manufactured AA6061 through the laser powder bed fusion(LPBF)process has been hindered by the pronounced formation of pores and cracks during rapid solidification.This study quantitatively investigated defects,including pores and cracks,and microstructures,including texture,grain size,subgrain structure,and precipitates,of LPBF-manufactured AA6061 across a broad spectrum of laser power and speed combinations.A high relative density of more than 99%was achieved with a low-power and low-speed condition,specifically 200 W and 100 mm s−1,with minimal cracks.Large pores,akin to or exceeding melt pool dimensions,emerged under either low or high energy densities,driven by the lack of fusion and vaporization/denudation mechanisms,re-spectively.Solidification cracks,confirmed by the fractography,were propagated along grain boundaries and are highly dependent on laser scanning speed.Elevated power and speed exhibited finer grain size with refined subgrain cellular structures and increased precipitates at interdendritic regions.The cooling rate and thermal gradient estimated from thermal analytical solutions explain the microstructures’char-acteristics.Nano-sized Si-Fe-Mg enriched precipitates are confirmed in both as-built and heat-treated conditions,whereas T6 heat treatment promotes a uniform distribution with coarsening of those precipi-tates.The low-power and low-speed conditions demonstrated the highest yield strength,consistent with defect levels.A minimum of 102.3%increase in yield strength with reduced ductility was observed after heat treatment for all examined conditions.This work sheds light on printing parameters to mitigate the formation of pores and cracks in additively manufactured AA6061,proposing a process window for op-timized fabrication and highlighting the potential for enhanced material properties and reduced defects through process control.
基金supported by National Natural Science Foundation of China(Grant No.U2006218)Project of Construction and Support for High-Level Innovative Teams of Beijing Municipal Institutions(Grant No.BPHR20220124).
文摘SiC is a wave-absorbing material with good dielectric properties,high-temperature resistance,and corrosion resistance,which has great potential for development in the field of high-temperature wave-absorbing.However,SiC is limited by its low impedance-matching performance and single wave-absorbing mechanism.Therefore,compatible metamaterial technologies are required to enhance its wave-absorbing performance further.The electromagnetic wave(EMW)absorbing metamaterials can realize perfect absorption of EMWs in specific frequency bands and precise regulation of EMW phase,propagation mode,and absorption frequency bands through structural changes.However,the traditional molding methods for manufacturing complex geometric shapes require expensive molds,involve process complexity,and have poor molding accuracy and other limitations.Therefore,additive manufacturing(AM)technology,through material layered stacking to achieve the processing of materials,is a comprehensive multidisciplinary advanced manufacturing technology and has become the core technology for manufacturing metamaterials.This review introduces the principles and applications of different AM technologies for SiC and related materials,discusses the current status and development trends of various AM technologies for fabricating silicon-carbon-based wave-absorbing metamaterials,summarizes the limitations and technological shortcomings of existing AM technologies for fabricating silicon-carbon-based wave-absorbing metamaterials,and provides an outlook for the future development of related AM technologies.
基金supported by the National Natural Science Foundation of China(No.52061135101 and 52001078)the German Research Foundation(DFG,No.448318292)+3 种基金the Technology Innovation Guidance Special Foundation of Shaanxi Province(No.2023GXLH-085)the Fundamental Research Funds for the Central Universities(No.D5000240161)the Project of Key areas of innovation team in Shaanxi Province(No.2024RS-CXTD-20)The author Yingchun Xie thanks the support from the National Key R&D Program(No.2023YFE0108000).
文摘1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-sized particles(5-50μm)to fabricate coatings[1-3].CS has been extensively used in a variety of coating applications,such as aerospace,automotive,energy,medical,marine,and others,to provide protection against high temperatures,corrosion,erosion,oxidation,and chemicals[4,5].Nowadays,the technical interest in CS is twofold:(i)as a repair process for damaged components,and(ii)as a solid-state additive manufacturing process.Compared to other fusion-based additive manufacturing(AM)technologies,Cold Spray Additive Manufacturing(CSAM)is a new member of the AM family that can enable the fabrication of deposits without undergoing melting.The chemical composition has been largely preserved from the powder to the deposit due to the minimal oxidation.The significant advantages of CSAM over other additive manufacturing processes include a high production rate,unlimited deposition size,high flexibility,and suitability for repairing damaged parts.
文摘Many strategies have been proposed to produce arenes from lignin as liquid fuel additives.However,the development of these methods is limited by the low yield of products,low atom utilization,and inefficient lignin depolymerization.Herein,we develop an energy-efficient synthetic method for the production of high-carbon-number arenes from sustainable lignin with a total yield of 23.1 wt%.Particularly,high carbon number arenes are obtained by fully utilizing the formaldehyde stabilizing additive and the methoxy group in lignin.The process begins with the reductive depolymerization of formaldehyde-stabilized lignin,followed by transmethylation between lignin monomers over Au/Nb_(2)O_(5) catalyst,and the Ru/Nb2O5-catalyzed hydrodeoxygenation.This work demonstrates the potential of value-added arenes production directly from lignin.
基金supported by the National Natural Science Foundation of China(Nos.52275299,52105313)R&D Program of Beijing Municipal Education Commission(No.KM202210005036)+1 种基金Natural Science Foundation of Chongqing,China(No.CSTB2023NSCQ-MSX0701)National Defense Basic Research Projects of China(No.JCKY2022405C002).
文摘Friction rolling additive manufacturing(FRAM)is a solid-state additive manufacturing technology that plasticizes the feed and deposits a material using frictional heat generated by the tool head.The thermal efficiency of FRAM,which depends only on friction to generate heat,is low,and the thermal-accumulation effect of the deposition process must be addressed.An FRAM heat-balance-control method that combines plasma-arc preheating and instant water cooling(PC-FRAM)is devised in this study,and a temperature field featuring rapidly increasing and decreasing temperature is constructed around the tool head.Additionally,2195-T87 Al-Li alloy is used as the feed material,and the effects of heating and cooling rates on the microstructure and mechanical properties are investigated.The results show that water cooling significantly improves heat accumulation during the deposition process.The cooling rate increases by 11.7 times,and the high-temperature residence time decreases by more than 50%.The grain size of the PC-FRAM sample is the smallest,i.e.,3.77±1.03μm,its dislocation density is the highest,and the number density of precipitates is the highest,the size of precipitates is the smallest,which shows the best precipitation-strengthening effect.The hardness test results are consistent with the precipitation distribution.The ultimate tensile strength,yield strength and elongation of the PC-FRAM samples are the highest(351±15.6 MPa,251.3±15.8 MPa and 16.25%±1.25%,respectively)among the samples investigated.The preheating and water-cooling-assisted deposition simultaneously increases the tensile strength and elongation of the deposited samples.The combination of preheating and instant cooling improves the deposition efficiency of FRAM and weakens the thermal-softening effect.
基金sponsored by the Science and Technology Program of Hubei Province,China(2022EHB020,2023BBB096)support provided by Centre of the Excellence in Production Research(XPRES)at KTH。
文摘In this review,we propose a comprehensive overview of additive manufacturing(AM)technologies and design possibilities in manufacturing metamaterials for various applications in the biomedical field,of which many are inspired by nature itself.It describes how new AM technologies(e.g.continuous liquid interface production and multiphoton polymerization,etc)and recent developments in more mature AM technologies(e.g.powder bed fusion,stereolithography,and extrusion-based bioprinting(EBB),etc)lead to more precise,efficient,and personalized biomedical components.EBB is a revolutionary topic creating intricate models with remarkable mechanical compatibility of metamaterials,for instance,stress elimination for tissue engineering and regenerative medicine,negative or zero Poisson’s ratio.By exploiting the designs of porous structures(e.g.truss,triply periodic minimal surface,plant/animal-inspired,and functionally graded lattices,etc),AM-made bioactive bone implants,artificial tissues,and organs are made for tissue replacement.The material palette of the AM metamaterials has high diversity nowadays,ranging from alloys and metals(e.g.cobalt-chromium alloys and titanium,etc)to polymers(e.g.biodegradable polycaprolactone and polymethyl methacrylate,etc),which could be even integrated within bioactive ceramics.These advancements are driving the progress of the biomedical field,improving human health and quality of life.
基金supported by the National Natural Science Foundation of China(Nos.52475317 and 52305331).
文摘In wire arc additive manufacturing(WAAM),a trade-off exists among deposition efficiency,microstructure,and mechanical properties.Addressing this challenge,this work proposes an innovative multi-objective optimization framework tailored for WAAM of AZ31 magnesium alloy components,which integrates deposition efficiency and microstructure as coupled objectives and is resolved through the NSGA-Ⅱ algorithm.The proposed framework employs quadratic regression to correlate process parameters with deposition efficiency through geometric morphology mediation,while addressing uncertainties in WAAM by integrating theoretical insights with data-driven stacked ensemble learning for grain size prediction,establishing the hybrid physics-informed data method for WAAM microstructure prediction.The optimized process achieved a deposition rate of 6257 mm3/min,with effective width and average layer height maintained at 10.1 mm and 4.13 mm,respectively.Microstructural optimization produced a fine,uniform,fully equiaxed grain structure with an average grain size of 38μm.These findings underscore the significant industrial potential of intelligent optimization strategies in WAAM for manufacturing lightweight,high-performance components in aerospace and transportation sectors.
基金financially supported by the National Key Re-search and Development Program of China(No.2023YFB4603301)Science Center for Gas Turbine Project(No.P2022-C-Ⅳ-002-001)+3 种基金National Natural Science Foundation of China(No.52401066)IMR Innovation Fund(No.2024-PY10)Project of TaiHang Laboratory(A3023)China Postdoctoral Science Foundation(No.2022M723211).
文摘Additive manufacturing(AM)technology has demonstrated significant potential in the green,lightweight,and functional development of metal materials,offering greater freedom and flexibility in the manufacturing process.However,the microstructural heterogeneity and mechanical property anisotropy of nickel-based superalloys along the build direction,stemming from thermal cycling,limit their widespread application in the aerospace industry.The proposed hybrid manufacturing process introduces external energy fields(thermal,ultrasonic,magnetic fields)into the forming processes,offering an innovative pathway to overcome the limitations of AM superalloys.This paper systematically discusses the influence of energy fields on the AM process of nickel-based superalloys,focusing on key issues such as cracking,porosity,microstructural heterogeneity,and mechanical property.Various energy fields modulate the melt pool dynamics and solidification process through distinct mechanisms.However,there remain several unresolved challenges and controversies regarding their mechanisms,particularly concerning the microstructural evolution under the synergistic effects of multiple energy fields.To address this issue,current studies predominantly focus on experimental validation,with a lack of unified theoretical models and numerical simulations,which limits the further development of energy field optimization strategies.Accordingly,the roles and advantages of various energy fields in AM of nickel-based superalloys are summarized.And engineering challenges are highlighted,such as multi-field synergistic control strategies,quantitative prediction models for microstructure-property,and energy field optimization methods for practical applications.Finally,the future trends of energy field-assisted AM for high-performance superalloys are discussed,with an outlook on its potential applications in re-manufacturing technologies and integrated equipment.
基金supported by a Discovery Early Career Researcher Award (DECRA,No.DE180101478) of the Australian Research CouncilNational Natural Science Foundation of China (Youth Program,No.52204378).
文摘Aqueous-electrolyte-based zinc-ion batteries(ZIBs),which have significant advantages over other batteries,including low cost,high safety,high ionic conductivity,and a natural abundance of zinc,have been regarded as a potential alternative to lithium-ion batteries(LIBs).ZIBs still face some critical challenges,however,especially for building a reversible zinc anode.To address the reversibility of zinc anode,great efforts have been made on intrinsic anode engineering and anode interface modification.Less attention has been devoted to the electrolyte additives,however,which could not only significantly improve the reversibility of zinc anode,but also determine the viability and overall performance of ZIBs.This review aims to provide an overview of the two main functions of electrolyte additives,followed by details on six reasons why additives might improve the performance of ZIBs from the perspectives of creating new layers and regulating current plating/stripping processes.Furthermore,the remaining difficulties and potential directions for additives in aqueous ZIBs are also highlighted.
