Smart manufacturing and Industry 4.0 are transforming traditional manufacturing processes by utilizing innovative technologies such as the artificial intelligence(AI)and internet of things(IoT)to enhance efficiency,re...Smart manufacturing and Industry 4.0 are transforming traditional manufacturing processes by utilizing innovative technologies such as the artificial intelligence(AI)and internet of things(IoT)to enhance efficiency,reduce costs,and ensure product quality.In light of the recent advancement of Industry 4.0,identifying defects has become important for ensuring the quality of products during the manufacturing process.In this research,we present an ensemble methodology for accurately classifying hot rolled steel surface defects by combining the strengths of four pre-trained convolutional neural network(CNN)architectures:VGG16,VGG19,Xception,and Mobile-Net V2,compensating for their individual weaknesses.We evaluated our methodology on the Xsteel surface defect dataset(XSDD),which comprises seven different classes.The ensemble methodology integrated the predictions of individual models through two methods:model averaging and weighted averaging.Our evaluation showed that the model averaging ensemble achieved an accuracy of 98.89%,a recall of 98.92%,a precision of 99.05%,and an F1-score of 98.97%,while the weighted averaging ensemble reached an accuracy of 99.72%,a recall of 99.74%,a precision of 99.67%,and an F1-score of 99.70%.The proposed weighted averaging ensemble model outperformed the model averaging method and the individual models in detecting defects in terms of accuracy,recall,precision,and F1-score.Comparative analysis with recent studies also showed the superior performance of our methodology.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
The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully ci...The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),respectively.With the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire deposits.Microstructure characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α phases.The mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and discussed.The mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat treatment.No fracture occurred within the interfacial area,further suggesting the robust interface.The findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.展开更多
A reasonable process plan is an important basis for implementing wire arc additive and subtractive hybrid manufacturing(ASHM),and a new optimization method is proposed.Firstly,the target parts and machining tools are ...A reasonable process plan is an important basis for implementing wire arc additive and subtractive hybrid manufacturing(ASHM),and a new optimization method is proposed.Firstly,the target parts and machining tools are modeled by level set functions.Secondly,the mathematical model of the additive direction optimization problem is established,and an improved particle swarm optimization algorithm is designed to decide the best additive direction.Then,the two-step strategy is used to plan the hybrid manufacturing alternating sequence.The target parts are directly divided into various processing regions;each processing region is optimized based on manufacturability and manufacturing efficiency,and the optimal hybrid manufacturing alternating sequence is obtained by merging some processing regions.Finally,the method is used to outline the process plan of the designed example model and applied to the actual hybrid manufacturing process of the model.The manufacturing result shows that the method can meet the main considerations in hybrid manufacturing.In addition,the degree of automation of process planning is high,and the dependence on manual intervention is low.展开更多
Intelligent manufacturing is a crucial path for promoting the transformation and upgrading of the manufacturing industr y. St andardization, connecting innovation, production, market s and ser v ices, plays an indispe...Intelligent manufacturing is a crucial path for promoting the transformation and upgrading of the manufacturing industr y. St andardization, connecting innovation, production, market s and ser v ices, plays an indispensable role in the development of intelligent manufacturing. This paper aims to explore the mechanism by which standardization aids in the high-quality development of the manufacturing industry in three aspects: standards are useful tools to identify the intelligent shortcomings of manufacturing enterprises;standards provide intelligent solutions for manufacturing enterprises;standards system guides the development of manufacturing industry. It is expected to provide insights for enterprises to facilitate their intelligent construction via standards, thereby boosting the intelligent development of the industry.展开更多
Piezoelectric and triboelectric effects are of growing interest for facilitating high-sensitivity and self-powered tactile sensor applications.The working principles of piezoelectric and triboelectric nanogenerators p...Piezoelectric and triboelectric effects are of growing interest for facilitating high-sensitivity and self-powered tactile sensor applications.The working principles of piezoelectric and triboelectric nanogenerators provide strategies for enhancing output voltage signals to achieve high sensitivity.Increasing the piezoelectric constant and surface triboelectric charge density are key factors in this enhancement.Methods such as annealing processes,doping techniques,grain orientation controls,crystallinity controls,and composite structures can effectively enhance the piezoelectric constant.For increasing triboelectric output,surface plasma treatment,charge injection,microstructuring,control of dielectric constant,and structural modification are effective methods.The fabrication methods present significant opportunities in tactile sensor applications.This review article summarizes the overall piezoelectric and triboelectric fabrication processes from materials to device aspects.It highlights applications in pressure,touch,bending,texture,distance,and material recognition sensors.The conclusion section addresses challenges and research opportunities,such as limited flexibility,stretchability,decoupling from multi-stimuli,multifunctional sensors,and data processing.展开更多
With the continuous development and wide application of modern technology,more enterprises and institutions in our country have begun to strengthen the research and manufacturing of intelligent elevators,aiming to bui...With the continuous development and wide application of modern technology,more enterprises and institutions in our country have begun to strengthen the research and manufacturing of intelligent elevators,aiming to build a new mode of modern manufacturing with the concept of green development as the core.Therefore,this paper takes green manufacturing as the background,analyzes the design significance of intelligent elevator lightweight,expounds its design ideas,and in the end introduces its specific design practice path.展开更多
Bionic interfaces exhibit multiscale features with various functions that reduce energy consumption and produce renewable resources to support life,triggering them an emerging area of technological revolution in many ...Bionic interfaces exhibit multiscale features with various functions that reduce energy consumption and produce renewable resources to support life,triggering them an emerging area of technological revolution in many disciplines.To improve the design and fabrication flexibility,additive manufacturing(AM)technology has been attempted to achieve multiscale structures and reconstruct biological functions at interfaces.Emerging AM of bionic interfaces has led to substantial advancements in renewable energy applications in recent years,but some challenges remain to be overcome.This review first presents a basic understanding of bionic mechanisms and typical manufacturing techniques especially AM.Subsequently,it emphasizes the latest progress of the bionic interfaces and AM on various renewable energy applications,such as those for wetting-controlled surfaces,energy harvesting,water treatment,batteries,and catalysts.Finally,it discusses some challenges and provides insights on how bionic interfaces and AM provide innovative solutions for next-generation renewable energy applications.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
The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial....The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial.Mixing intensification encompasses innovative methods and tools that address the limitations of inadequate mixing within reactors,enabling efficient reaction scaling and boosting the productivity of industrial processes.This review provides a concise introduction to the fundamentals of multiphase mixing,followed by case studies highlighting the application of mixing intensification in the production of energy-storage materials,advanced optical materials,and nanopesticides.These examples illustrate the significance of theoretical analysis in informing and advancing engineering practices within the chemical industry.We also explore the challenges and opportunities in this field,offering insights based on our current understanding.展开更多
With the advancement and maturation of digital technology,immersive experiences,virtual interactive systems,and real physical environments are combined to create an independent“digital twin”world.In the field of int...With the advancement and maturation of digital technology,immersive experiences,virtual interactive systems,and real physical environments are combined to create an independent“digital twin”world.In the field of intelligent manufacturing,there is a growing need to explore and develop a new platform for practical teaching based on digital twins,in line with the intelligent,networked,and digital transformation of education.By analyzing the design elements of this platform,building various digital twin prototypes and environments,and developing a teaching and training platform for intelligent manufacturing based on digital twins,significant improvements can be achieved in efficiency.Therefore,this paper discusses the development of an intelligent manufacturing teaching and training platform based on digital twins,aiming to enrich both the form and content of intelligent manufacturing training.展开更多
With the urgent demand for lightweight and integrated structural parts in the aerospacefield,the use of cold metal transfer wire arc additive manufacturing(CMT-WAAM)to form large-size magnesium alloy structural parts h...With the urgent demand for lightweight and integrated structural parts in the aerospacefield,the use of cold metal transfer wire arc additive manufacturing(CMT-WAAM)to form large-size magnesium alloy structural parts has become a research hotspot.In this paper,a large AZ31 magnesium alloy multilayer block with a lower porosity was successfully prepared by CMT-WAAM.The AZ31 block exhibits a fully equiaxed grain morphology,the average grain diameters of the top,middle,and bottom are 16.1μm,12.4μm,and 10.4μm,respectively.The submicron spherical particles measuring 0.09 to 0.4μm are Mg17Al12 phases,irregular particles are Al8Mn5+Mg17Al12 composite phases and large particles measuring 5 to 10μm are Al8Mn5 in AZ31 block.The UTS of CMT-WAAM AZ31 block from the bottom of 239.9±5.0 MPa to the top of 237.3±3.1 MPa,and the EL from the bottom of 22.7±0.6%to the top of 30.0±1.1%,exceeding the casting standards.In the CMT-WAAM processed AZ31 alloy,the pre-existing coarse second phase particles in the AZ31filaments acted as nucleating agents,and the electromagnetic stirring effect in the WAAM process broke up the dendrites and increased the number density of nucleation sites to improve the rate of nucleation,and the complex thermal conditions in the WAAM process restricted the growth of the grains and the precipitated phases.The mechanical properties of AZ31 alloy were improved by effectively refining its grain size and precipitated phase size.展开更多
Machine learning(ML)has recently enabled many modeling tasks in design,manufacturing,and condition monitoring due to its unparalleled learning ability using existing data.Data have become the limiting factor when impl...Machine learning(ML)has recently enabled many modeling tasks in design,manufacturing,and condition monitoring due to its unparalleled learning ability using existing data.Data have become the limiting factor when implementing ML in industry.However,there is no systematic investigation on how data quality can be assessed and improved for ML-based design and manufacturing.The aim of this survey is to uncover the data challenges in this domain and review the techniques used to resolve them.To establish the background for the subsequent analysis,crucial data terminologies in ML-based modeling are reviewed and categorized into data acquisition,management,analysis,and utilization.Thereafter,the concepts and frameworks established to evaluate data quality and imbalance,including data quality assessment,data readiness,information quality,data biases,fairness,and diversity,are further investigated.The root causes and types of data challenges,including human factors,complex systems,complicated relationships,lack of data quality,data heterogeneity,data imbalance,and data scarcity,are identified and summarized.Methods to improve data quality and mitigate data imbalance and their applications in this domain are reviewed.This literature review focuses on two promising methods:data augmentation and active learning.The strengths,limitations,and applicability of the surveyed techniques are illustrated.The trends of data augmentation and active learning are discussed with respect to their applications,data types,and approaches.Based on this discussion,future directions for data quality improvement and data imbalance mitigation in this domain are identified.展开更多
This study evaluates the Fuzzy Analytical Hierarchy Process(FAHP)as a multi-criteria decision(MCD)support tool for selecting appropriate additive manufacturing(AM)techniques that align with cleaner production and envi...This study evaluates the Fuzzy Analytical Hierarchy Process(FAHP)as a multi-criteria decision(MCD)support tool for selecting appropriate additive manufacturing(AM)techniques that align with cleaner production and environmental sustainability.The FAHP model was validated using an example of the production of aircraft components(specifically fuselage)employing AM technologies such as Wire Arc Additive Manufacturing(WAAM),laser powder bed fusion(L-PBF),Binder Jetting(BJ),Selective Laser Sintering(SLS),and Laser Metal Deposition(LMD).The selection criteria prioritized eco-friendly manufacturing considerations,including the quality and properties of the final product(e.g.,surface finish,high strength,and corrosion resistance),service and functional requirements,weight reduction for improved energy efficiency(lightweight structures),and environmental responsibility.Sustainability metrics,such as cost-effectiveness,material efficiency,waste minimization,and environmental impact,are central to the evaluation process.A computer-aided modeling approach was also used to simulate the performance of aluminum(AA7075 T6),steel(304),and titanium alloy(Ti6Al4V)for fuselage development.The results demonstrate that MCD approaches such as FAHP can effectively guide the selection of AM technologies that meet functional and technical requirements while minimizing environmental degradation footprints.Furthermore,the aluminumalloy outperformed the other materials investigated in the simulation with the lowest stress concentration and least deformation.This study contributes to advancing cleaner production practices by providing a decision-making framework for sustainable and eco-friendly manufacturing,enabling manufacturers to adopt AM technologies that promote environmental responsibility and sustainable development,while maintaining product quality and performance.展开更多
Chimeric antigen receptor natural killer(CAR-NK)cell therapy is an alternative immunotherapy that provides robust tumor-eliminating effects without inducing life-threatening toxicities and graft-versus-host disease.CA...Chimeric antigen receptor natural killer(CAR-NK)cell therapy is an alternative immunotherapy that provides robust tumor-eliminating effects without inducing life-threatening toxicities and graft-versus-host disease.CAR-NK cell therapy has enabled the development of“off-the-shelf”products that bypass the lengthy and expensive cell manufacturing process1.展开更多
According to different damage modes,warheads are roughly divided into three types:fragmentation warheads,shaped charge warheads,and penetrating warheads.Due to limitations in material and structural manufacturing,trad...According to different damage modes,warheads are roughly divided into three types:fragmentation warheads,shaped charge warheads,and penetrating warheads.Due to limitations in material and structural manufacturing,traditional manufacturing methods make it difficult to fully utilize the damage ability of the warhead.Additive manufacturing(AM)technology can fabricate complex structures,with classified materials composition and customized components,while achieving low cost,high accuracy,and rapid production of the parts.The maturity of AM technology has brought about a new round of revolution in the field of warheads.In this paper,we first review the principles,classifications,and characteristics of different AM technologies.The development trends of AM technologies are pointed out,including multi-material AM technology,hybrid AM technology,and smart AM technology.From our survey,PBF,DED,and EBM technologies are mainly used to manufacture warhead damage elements.FDM and DIW technologies are mainly used to manufacture warhead charges.Then,the research on the application of AM technology in three types of warhead and warhead charges was reviewed and the existing problems and progress of AM technologies in each warhead were analyzed.Finally,we summarized the typical applications and look forward to the application prospects of AM technology in the field of warheads.展开更多
Powder bed fusion(PBF)in metallic additive manufacturing offers the ability to produce intricate geometries,high-strength components,and reliable products.However,powder processing before energy-based binding signific...Powder bed fusion(PBF)in metallic additive manufacturing offers the ability to produce intricate geometries,high-strength components,and reliable products.However,powder processing before energy-based binding significantly impacts the final product’s integrity.Processing maps guide efficient process design to minimize defects,but creating them through experimentation alone is challenging due to the wide range of parameters,necessitating a comprehensive computational parametric analysis.In this study,we used the discrete element method to parametrically analyze the powder processing design space in PBF of stainless steel 316L powders.Uniform lattice parameter sweeps are often used for parametric analysis,but are computationally intensive.We find that non-uniform parameter sweep based on the low discrepancy sequence(LDS)algorithm is ten times more efficient at exploring the design space while accurately capturing the relationship between powder flow dynamics and bed packing density.We introduce a multi-layer perceptron(MLP)model to interpolate parametric causalities within the LDS parameter space.With over 99%accuracy,it effectively captures these causalities while requiring fewer simulations.Finally,we generate processing design maps for machine setups and powder selections for efficient process design.We find that recoating speed has the highest impact on powder processing quality,followed by recoating layer thickness,particle size,and inter-particle friction.展开更多
As a key sector in advancing China’s“carbon neutrality”goal,the machinery manufacturing industry has achieved remarkable development in recent years.Against this backdrop,the scientific and objective evaluation of ...As a key sector in advancing China’s“carbon neutrality”goal,the machinery manufacturing industry has achieved remarkable development in recent years.Against this backdrop,the scientific and objective evaluation of the financial performance of machinery manufacturing enterprises has become a pressing issue in financial research.This topic is not only crucial for optimizing enterprise management and improving operational efficiency but also essential for enhancing overall industry performance and promoting sustainable development.This paper first introduces the concept of financial performance,followed by an analysis of related financial performance evaluation theories.It then focuses on the application of the entropy method in evaluating the financial performance of machinery manufacturing enterprises,detailing its analytical steps.Finally,a financial performance evaluation index system is constructed based on four dimensions:profitability,solvency,operational efficiency,and growth potential.展开更多
To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,t...To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,thereby improving both microstructure uniformity and mechanical properties of sintered bodies.The results indicate that WIP reduces defects in MEX greens,thus decreasing the dimensions and numbers of defects,modifying shapes of pores within sintered bodies,while preserving surface quality and shape characteristics.Compared with WC-9Co prepared via MEX followed by debinding and sintering(DS),the hardness of WC-9Co prepared using MEX-WIP-DS does not change significantly,ranging HV_(30)1494-1508,the transverse rupture strength increases by up to 49.3%,reaching 2998-3514 MPa,and the fracture toughness remains high,ranging 14.8-17.0 MPa·m^(1/2).The mechanical properties surpass comparable cemented carbides fabricated through other AM methods and are comparable to those produced by powder metallurgy.The integration of green WIP into MEX-DS broadens the MEX processing window,and improves the overall mechanical properties of MEX AM WC-Co cemented carbides.展开更多
Owing to the lack of matching commercial welding wires,the development of wire arc additive manufacturing(WAAM)for most aluminum alloys is hindered.A wire-powder synchronous arc additive manufacturing(WPAAM)was propos...Owing to the lack of matching commercial welding wires,the development of wire arc additive manufacturing(WAAM)for most aluminum alloys is hindered.A wire-powder synchronous arc additive manufacturing(WPAAM)was proposed to prepare the target Al-Si-Mg aluminum alloy.Based on the synchronous deposition of AlSi_(12) wire and pure Mg powder,the deposition width of the WPAAMed thin-wall was increased by 61% compared with that of WAAMed thin-wall using AlSi_(12) wire,and the machining allowance was reduced by 81%.The added Mg powder benefited to form refined equiaxed grains,and reduced the average grain size of the WPAAMed thin-wall to 47.1μm,showing a decrease of 23.8% relatively to that of the WAAMed thin-wall.Besides,Mg reacted with Si to form Mg_(2)Si strengthening phases.The mechanical properties tests showed that the ultimate tensile strength and elongation of the WPAAMed thin-wall increased up to 174.5 MPa and 4.1%,reaching 92% and 60% those of the WAAMed thin-wall,respectively.展开更多
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2022R1I1A3063493).
文摘Smart manufacturing and Industry 4.0 are transforming traditional manufacturing processes by utilizing innovative technologies such as the artificial intelligence(AI)and internet of things(IoT)to enhance efficiency,reduce costs,and ensure product quality.In light of the recent advancement of Industry 4.0,identifying defects has become important for ensuring the quality of products during the manufacturing process.In this research,we present an ensemble methodology for accurately classifying hot rolled steel surface defects by combining the strengths of four pre-trained convolutional neural network(CNN)architectures:VGG16,VGG19,Xception,and Mobile-Net V2,compensating for their individual weaknesses.We evaluated our methodology on the Xsteel surface defect dataset(XSDD),which comprises seven different classes.The ensemble methodology integrated the predictions of individual models through two methods:model averaging and weighted averaging.Our evaluation showed that the model averaging ensemble achieved an accuracy of 98.89%,a recall of 98.92%,a precision of 99.05%,and an F1-score of 98.97%,while the weighted averaging ensemble reached an accuracy of 99.72%,a recall of 99.74%,a precision of 99.67%,and an F1-score of 99.70%.The proposed weighted averaging ensemble model outperformed the model averaging method and the individual models in detecting defects in terms of accuracy,recall,precision,and F1-score.Comparative analysis with recent studies also showed the superior performance of our methodology.
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financially supported by the Agency for Science,Technology and Research(A*Star),Republic of Singapore,under the Aerospace Consortium Cycle 12“Characterization of the Effect of Wire and Powder Deposited Materials”(No.A1815a0078)。
文摘The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),respectively.With the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire deposits.Microstructure characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α phases.The mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and discussed.The mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat treatment.No fracture occurred within the interfacial area,further suggesting the robust interface.The findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.
基金The National Natural Science Foundation of China(No.52305381)the Natural Science Foundation of Jiangsu Province(No.BK20210351)the Fundamental Research Funds for the Central Universities(No.30923011008).
文摘A reasonable process plan is an important basis for implementing wire arc additive and subtractive hybrid manufacturing(ASHM),and a new optimization method is proposed.Firstly,the target parts and machining tools are modeled by level set functions.Secondly,the mathematical model of the additive direction optimization problem is established,and an improved particle swarm optimization algorithm is designed to decide the best additive direction.Then,the two-step strategy is used to plan the hybrid manufacturing alternating sequence.The target parts are directly divided into various processing regions;each processing region is optimized based on manufacturability and manufacturing efficiency,and the optimal hybrid manufacturing alternating sequence is obtained by merging some processing regions.Finally,the method is used to outline the process plan of the designed example model and applied to the actual hybrid manufacturing process of the model.The manufacturing result shows that the method can meet the main considerations in hybrid manufacturing.In addition,the degree of automation of process planning is high,and the dependence on manual intervention is low.
文摘Intelligent manufacturing is a crucial path for promoting the transformation and upgrading of the manufacturing industr y. St andardization, connecting innovation, production, market s and ser v ices, plays an indispensable role in the development of intelligent manufacturing. This paper aims to explore the mechanism by which standardization aids in the high-quality development of the manufacturing industry in three aspects: standards are useful tools to identify the intelligent shortcomings of manufacturing enterprises;standards provide intelligent solutions for manufacturing enterprises;standards system guides the development of manufacturing industry. It is expected to provide insights for enterprises to facilitate their intelligent construction via standards, thereby boosting the intelligent development of the industry.
基金supported by National Research Foundation of Korea(2022M3D1A2054488)Technology Innovation Program(20025736,Development of MICS SoC and platform for in-vivo implantable electroceutical device)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)。
文摘Piezoelectric and triboelectric effects are of growing interest for facilitating high-sensitivity and self-powered tactile sensor applications.The working principles of piezoelectric and triboelectric nanogenerators provide strategies for enhancing output voltage signals to achieve high sensitivity.Increasing the piezoelectric constant and surface triboelectric charge density are key factors in this enhancement.Methods such as annealing processes,doping techniques,grain orientation controls,crystallinity controls,and composite structures can effectively enhance the piezoelectric constant.For increasing triboelectric output,surface plasma treatment,charge injection,microstructuring,control of dielectric constant,and structural modification are effective methods.The fabrication methods present significant opportunities in tactile sensor applications.This review article summarizes the overall piezoelectric and triboelectric fabrication processes from materials to device aspects.It highlights applications in pressure,touch,bending,texture,distance,and material recognition sensors.The conclusion section addresses challenges and research opportunities,such as limited flexibility,stretchability,decoupling from multi-stimuli,multifunctional sensors,and data processing.
文摘With the continuous development and wide application of modern technology,more enterprises and institutions in our country have begun to strengthen the research and manufacturing of intelligent elevators,aiming to build a new mode of modern manufacturing with the concept of green development as the core.Therefore,this paper takes green manufacturing as the background,analyzes the design significance of intelligent elevator lightweight,expounds its design ideas,and in the end introduces its specific design practice path.
基金supported by the Guangdong Province Science and Technology Plan Project 2023B1212120008Shenzhen Science and Technology Program JCYJ20220818101204010+1 种基金RGC Theme-based Research Scheme AoE/M-402/20Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Materials Engineering Research Center.
文摘Bionic interfaces exhibit multiscale features with various functions that reduce energy consumption and produce renewable resources to support life,triggering them an emerging area of technological revolution in many disciplines.To improve the design and fabrication flexibility,additive manufacturing(AM)technology has been attempted to achieve multiscale structures and reconstruct biological functions at interfaces.Emerging AM of bionic interfaces has led to substantial advancements in renewable energy applications in recent years,but some challenges remain to be overcome.This review first presents a basic understanding of bionic mechanisms and typical manufacturing techniques especially AM.Subsequently,it emphasizes the latest progress of the bionic interfaces and AM on various renewable energy applications,such as those for wetting-controlled surfaces,energy harvesting,water treatment,batteries,and catalysts.Finally,it discusses some challenges and provides insights on how bionic interfaces and AM provide innovative solutions for next-generation renewable energy applications.
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(22288102,22035007,and 22122815)。
文摘The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial.Mixing intensification encompasses innovative methods and tools that address the limitations of inadequate mixing within reactors,enabling efficient reaction scaling and boosting the productivity of industrial processes.This review provides a concise introduction to the fundamentals of multiphase mixing,followed by case studies highlighting the application of mixing intensification in the production of energy-storage materials,advanced optical materials,and nanopesticides.These examples illustrate the significance of theoretical analysis in informing and advancing engineering practices within the chemical industry.We also explore the challenges and opportunities in this field,offering insights based on our current understanding.
文摘With the advancement and maturation of digital technology,immersive experiences,virtual interactive systems,and real physical environments are combined to create an independent“digital twin”world.In the field of intelligent manufacturing,there is a growing need to explore and develop a new platform for practical teaching based on digital twins,in line with the intelligent,networked,and digital transformation of education.By analyzing the design elements of this platform,building various digital twin prototypes and environments,and developing a teaching and training platform for intelligent manufacturing based on digital twins,significant improvements can be achieved in efficiency.Therefore,this paper discusses the development of an intelligent manufacturing teaching and training platform based on digital twins,aiming to enrich both the form and content of intelligent manufacturing training.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFB3712005).
文摘With the urgent demand for lightweight and integrated structural parts in the aerospacefield,the use of cold metal transfer wire arc additive manufacturing(CMT-WAAM)to form large-size magnesium alloy structural parts has become a research hotspot.In this paper,a large AZ31 magnesium alloy multilayer block with a lower porosity was successfully prepared by CMT-WAAM.The AZ31 block exhibits a fully equiaxed grain morphology,the average grain diameters of the top,middle,and bottom are 16.1μm,12.4μm,and 10.4μm,respectively.The submicron spherical particles measuring 0.09 to 0.4μm are Mg17Al12 phases,irregular particles are Al8Mn5+Mg17Al12 composite phases and large particles measuring 5 to 10μm are Al8Mn5 in AZ31 block.The UTS of CMT-WAAM AZ31 block from the bottom of 239.9±5.0 MPa to the top of 237.3±3.1 MPa,and the EL from the bottom of 22.7±0.6%to the top of 30.0±1.1%,exceeding the casting standards.In the CMT-WAAM processed AZ31 alloy,the pre-existing coarse second phase particles in the AZ31filaments acted as nucleating agents,and the electromagnetic stirring effect in the WAAM process broke up the dendrites and increased the number density of nucleation sites to improve the rate of nucleation,and the complex thermal conditions in the WAAM process restricted the growth of the grains and the precipitated phases.The mechanical properties of AZ31 alloy were improved by effectively refining its grain size and precipitated phase size.
基金funded by the McGill University Graduate Excellence Fellowship Award(00157)the Mitacs Accelerate Program(IT13369)the McGill Engineering Doctoral Award(MEDA).
文摘Machine learning(ML)has recently enabled many modeling tasks in design,manufacturing,and condition monitoring due to its unparalleled learning ability using existing data.Data have become the limiting factor when implementing ML in industry.However,there is no systematic investigation on how data quality can be assessed and improved for ML-based design and manufacturing.The aim of this survey is to uncover the data challenges in this domain and review the techniques used to resolve them.To establish the background for the subsequent analysis,crucial data terminologies in ML-based modeling are reviewed and categorized into data acquisition,management,analysis,and utilization.Thereafter,the concepts and frameworks established to evaluate data quality and imbalance,including data quality assessment,data readiness,information quality,data biases,fairness,and diversity,are further investigated.The root causes and types of data challenges,including human factors,complex systems,complicated relationships,lack of data quality,data heterogeneity,data imbalance,and data scarcity,are identified and summarized.Methods to improve data quality and mitigate data imbalance and their applications in this domain are reviewed.This literature review focuses on two promising methods:data augmentation and active learning.The strengths,limitations,and applicability of the surveyed techniques are illustrated.The trends of data augmentation and active learning are discussed with respect to their applications,data types,and approaches.Based on this discussion,future directions for data quality improvement and data imbalance mitigation in this domain are identified.
文摘This study evaluates the Fuzzy Analytical Hierarchy Process(FAHP)as a multi-criteria decision(MCD)support tool for selecting appropriate additive manufacturing(AM)techniques that align with cleaner production and environmental sustainability.The FAHP model was validated using an example of the production of aircraft components(specifically fuselage)employing AM technologies such as Wire Arc Additive Manufacturing(WAAM),laser powder bed fusion(L-PBF),Binder Jetting(BJ),Selective Laser Sintering(SLS),and Laser Metal Deposition(LMD).The selection criteria prioritized eco-friendly manufacturing considerations,including the quality and properties of the final product(e.g.,surface finish,high strength,and corrosion resistance),service and functional requirements,weight reduction for improved energy efficiency(lightweight structures),and environmental responsibility.Sustainability metrics,such as cost-effectiveness,material efficiency,waste minimization,and environmental impact,are central to the evaluation process.A computer-aided modeling approach was also used to simulate the performance of aluminum(AA7075 T6),steel(304),and titanium alloy(Ti6Al4V)for fuselage development.The results demonstrate that MCD approaches such as FAHP can effectively guide the selection of AM technologies that meet functional and technical requirements while minimizing environmental degradation footprints.Furthermore,the aluminumalloy outperformed the other materials investigated in the simulation with the lowest stress concentration and least deformation.This study contributes to advancing cleaner production practices by providing a decision-making framework for sustainable and eco-friendly manufacturing,enabling manufacturers to adopt AM technologies that promote environmental responsibility and sustainable development,while maintaining product quality and performance.
基金supported by grants from the Noncommunicable Chronic Diseases-National Science and Technology Major Project(Grant No.2023ZD0501300)Science Technology Department of Zhejiang Province(Grant No.2021C03117)+2 种基金National Natural Science Foundation of China(Grant No.82350104 and 82170219)Natural Science Foundation of Zhejiang Province,China(Grant No.LY23H080004 and LY24H080001)Medical Health Science and Technology Project of Zhejiang Provincial Health Commission(Grant No.2021KY199)。
文摘Chimeric antigen receptor natural killer(CAR-NK)cell therapy is an alternative immunotherapy that provides robust tumor-eliminating effects without inducing life-threatening toxicities and graft-versus-host disease.CAR-NK cell therapy has enabled the development of“off-the-shelf”products that bypass the lengthy and expensive cell manufacturing process1.
基金sponsored by the National Key Research and Development Program of China(Grant No.2022YFC3320500)the National Natural Science Foundation of China(Grant Nos.12372333,12221002 and 12072037)。
文摘According to different damage modes,warheads are roughly divided into three types:fragmentation warheads,shaped charge warheads,and penetrating warheads.Due to limitations in material and structural manufacturing,traditional manufacturing methods make it difficult to fully utilize the damage ability of the warhead.Additive manufacturing(AM)technology can fabricate complex structures,with classified materials composition and customized components,while achieving low cost,high accuracy,and rapid production of the parts.The maturity of AM technology has brought about a new round of revolution in the field of warheads.In this paper,we first review the principles,classifications,and characteristics of different AM technologies.The development trends of AM technologies are pointed out,including multi-material AM technology,hybrid AM technology,and smart AM technology.From our survey,PBF,DED,and EBM technologies are mainly used to manufacture warhead damage elements.FDM and DIW technologies are mainly used to manufacture warhead charges.Then,the research on the application of AM technology in three types of warhead and warhead charges was reviewed and the existing problems and progress of AM technologies in each warhead were analyzed.Finally,we summarized the typical applications and look forward to the application prospects of AM technology in the field of warheads.
基金supported by the funding provided by Boeing Center for Aviation and Aerospace Safety.
文摘Powder bed fusion(PBF)in metallic additive manufacturing offers the ability to produce intricate geometries,high-strength components,and reliable products.However,powder processing before energy-based binding significantly impacts the final product’s integrity.Processing maps guide efficient process design to minimize defects,but creating them through experimentation alone is challenging due to the wide range of parameters,necessitating a comprehensive computational parametric analysis.In this study,we used the discrete element method to parametrically analyze the powder processing design space in PBF of stainless steel 316L powders.Uniform lattice parameter sweeps are often used for parametric analysis,but are computationally intensive.We find that non-uniform parameter sweep based on the low discrepancy sequence(LDS)algorithm is ten times more efficient at exploring the design space while accurately capturing the relationship between powder flow dynamics and bed packing density.We introduce a multi-layer perceptron(MLP)model to interpolate parametric causalities within the LDS parameter space.With over 99%accuracy,it effectively captures these causalities while requiring fewer simulations.Finally,we generate processing design maps for machine setups and powder selections for efficient process design.We find that recoating speed has the highest impact on powder processing quality,followed by recoating layer thickness,particle size,and inter-particle friction.
文摘As a key sector in advancing China’s“carbon neutrality”goal,the machinery manufacturing industry has achieved remarkable development in recent years.Against this backdrop,the scientific and objective evaluation of the financial performance of machinery manufacturing enterprises has become a pressing issue in financial research.This topic is not only crucial for optimizing enterprise management and improving operational efficiency but also essential for enhancing overall industry performance and promoting sustainable development.This paper first introduces the concept of financial performance,followed by an analysis of related financial performance evaluation theories.It then focuses on the application of the entropy method in evaluating the financial performance of machinery manufacturing enterprises,detailing its analytical steps.Finally,a financial performance evaluation index system is constructed based on four dimensions:profitability,solvency,operational efficiency,and growth potential.
基金supported by the Key Project of Chinese Academy of Engineering(No.2019-XZ-11)the General Project of Chinese Academy of Engineering(No.2023-XY-18)+1 种基金the Open Fund of National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials of China(No.HKDNM201907)the Independent Project of State Key Laboratory of Powder Metallurgy,China。
文摘To tackle the common issue of green defects in material extrusion(MEX)additive manufacturing(AM)cemented carbides,warm isostatic pressing(WIP)was introduced to eliminate defects of MEX WC-9Co cemented carbide greens,thereby improving both microstructure uniformity and mechanical properties of sintered bodies.The results indicate that WIP reduces defects in MEX greens,thus decreasing the dimensions and numbers of defects,modifying shapes of pores within sintered bodies,while preserving surface quality and shape characteristics.Compared with WC-9Co prepared via MEX followed by debinding and sintering(DS),the hardness of WC-9Co prepared using MEX-WIP-DS does not change significantly,ranging HV_(30)1494-1508,the transverse rupture strength increases by up to 49.3%,reaching 2998-3514 MPa,and the fracture toughness remains high,ranging 14.8-17.0 MPa·m^(1/2).The mechanical properties surpass comparable cemented carbides fabricated through other AM methods and are comparable to those produced by powder metallurgy.The integration of green WIP into MEX-DS broadens the MEX processing window,and improves the overall mechanical properties of MEX AM WC-Co cemented carbides.
基金supported by the National Natural Science Foundation of China(No.52205360)。
文摘Owing to the lack of matching commercial welding wires,the development of wire arc additive manufacturing(WAAM)for most aluminum alloys is hindered.A wire-powder synchronous arc additive manufacturing(WPAAM)was proposed to prepare the target Al-Si-Mg aluminum alloy.Based on the synchronous deposition of AlSi_(12) wire and pure Mg powder,the deposition width of the WPAAMed thin-wall was increased by 61% compared with that of WAAMed thin-wall using AlSi_(12) wire,and the machining allowance was reduced by 81%.The added Mg powder benefited to form refined equiaxed grains,and reduced the average grain size of the WPAAMed thin-wall to 47.1μm,showing a decrease of 23.8% relatively to that of the WAAMed thin-wall.Besides,Mg reacted with Si to form Mg_(2)Si strengthening phases.The mechanical properties tests showed that the ultimate tensile strength and elongation of the WPAAMed thin-wall increased up to 174.5 MPa and 4.1%,reaching 92% and 60% those of the WAAMed thin-wall,respectively.
