Based on the theory of elastic mechanics and material mechanics, the orientation precision of the hohl schaft kegel（HSK） tooling system in static and dynamic states is theoretically and experimentally studied. The r...Based on the theory of elastic mechanics and material mechanics, the orientation precision of the hohl schaft kegel（HSK） tooling system in static and dynamic states is theoretically and experimentally studied. The relation between the clamping force and the shank taper is obtained. And a proper clamping force is found to be essential to assure the axial and radial orientation precisions of the HSK tooling system in high speed machining （HSM）. Analytical results show that the reason why the HSK tooling system can keep high precision at the high rotational speed is that the actual axial clamping force keeps the two surfaces of the shank and the spindle in contact all the time.展开更多
According to the structure of the hohl schaft kegel（HSK） tooling system and its working principle, a mechanical model of the HSK tooling system is established. Major factors influencing the stiffness of the system a...According to the structure of the hohl schaft kegel（HSK） tooling system and its working principle, a mechanical model of the HSK tooling system is established. Major factors influencing the stiffness of the system are analyzed and the relationship between the load and the manufacturing quality is obtained. The basic rule of the stiffness variation is presented and the theoretical analysis is in a good agreement with experimental results. The dynamic stiffness must also be considered to evaluate the performance of the tooling system besides the staticstiffness. Finally, the selecting principles of the HSK types are proposed and their optimum operating conditions are established.展开更多
Thermal fatigue and high temperature wear are the two principle failure mechanisms for thixoforming dies. Samples of Inconel 617 and Stellite 6 alloys were submitted to thermal cycling under conditions which approxima...Thermal fatigue and high temperature wear are the two principle failure mechanisms for thixoforming dies. Samples of Inconel 617 and Stellite 6 alloys were submitted to thermal cycling under conditions which approximate thixoforming of steels and to sliding wear tests at 750 ℃. The experimental results thus obtained were compared with those of the X32CrMoV33 hot work tool steel. The Inconel 617 and Stellite 6 samples are much more resistant to oxidation and to softening than the hot work tool steel, providing a superior resistance to thermal fatigue cracking. The wear resistance of the Inconel 617 and Stellite 6 alloys at 750 ℃ is also markedly superior. The adhesive oxides growing slowly on Inconel 617 and Stellite 6 alloys sustain the wear action without spalling and are claimed to be responsible for the superior wear resistance of these alloys at 750 ℃.展开更多
The present work compares microstructures of hot work steels made by different processes, that is, by sprayforming,by casting, and a commercially supplied H13 steel. Material benefits are recognized by sprayforming ho...The present work compares microstructures of hot work steels made by different processes, that is, by sprayforming,by casting, and a commercially supplied H13 steel. Material benefits are recognized by sprayforming hot working tools such as die inserts for hot forging. The sprayformed hot work steels present a fine and homogeneous microstructure,which implies that, at a similar toughness level, the sprayformed steel can be higher alloyed, so that the thermal fatigue and wear resistance at elevated temperatures can be improved. A series of steels with higher vanadium content than commercial hot work steels are developed. There are no segregation and carbide network problems usually encountered in conventional ingot/forging processed high-vanadium steels. Microstructure and hardness of the new sprayformed steels are studied under different heat treatment conditions. It is justified that these sprayformed steels can be directly used for tooling without high temperature hardening. Sprayforming the tool steels onto a precision ceramic mould is demonstrated to extend the technoeconomical benefits, so that a net shape production tool can be rapidly made.Features of the rapid tooling process are also discussed.展开更多
Thixoforging is a type of semi-solid metal processing at high solid fraction (0.7<φs<1), which involves the processing of alloys in the semi-solid state.Tooling has to be adapted to this particular process to b...Thixoforging is a type of semi-solid metal processing at high solid fraction (0.7<φs<1), which involves the processing of alloys in the semi-solid state.Tooling has to be adapted to this particular process to benefit shear thinning and thixotropic behaviour of such semi-solid material.Tooling parameters, such as the forming speed and tool temperature, have to be accurately controlled because of their influence on thermal exchanges between material flow and tool.These thermal exchanges influence the high-cracking tendency and the rheology of the semi-solid material during forming, which affects parts properties and therefore their quality.Extrusion tests show how thermal exchanges influence quality of thixoforged parts made of 7075 aluminium alloys at high solid fraction by modifying process parameters like forming speed, tool temperature and tool thermal protector.Thus an optimum in terms of thermal exchanges has to be found between surface quality and mechanical properties of the part.A direct application is the evaluation of surface quality of thixoforged thin wall parts made of 7075 aluminium alloy.展开更多
X32CrMoV33 hot work tool steel samples coated with AlTiN and AlTiON were submitted to thermal cycling under conditions that approximate thixoforming of steels and to sliding wear tests at 750 ℃,measured to be the cav...X32CrMoV33 hot work tool steel samples coated with AlTiN and AlTiON were submitted to thermal cycling under conditions that approximate thixoforming of steels and to sliding wear tests at 750 ℃,measured to be the cavity surface temperature shortly after the steel slurry is forced into the thixoforming die.AlTiN and AlTiON coatings provide adequate protection against oxidation of the tool steel substrate,but fail to avoid thermal fatigue cracking.This is attributed to the extensive softening of the substrate,the thermal expansion mismatch between the hot work tool steel and the coatings and residual compressive stresses inherited from the deposition process.The impact of AlTiN and AlTiON coatings on the high temperature wear resistance,on the other hand,is favourable.The improved wear resistance is attributed to the stable,protective surface oxide films.展开更多
Rapid tooling technique based on the sterelithograph prototype is investigated. The epoxy tooling technological process was elucidated. It is analyzed in detail that the epoxy resin formula is easy to cast, curing pro...Rapid tooling technique based on the sterelithograph prototype is investigated. The epoxy tooling technological process was elucidated. It is analyzed in detail that the epoxy resin formula is easy to cast, curing process, and release agents. The transitional plaster model is also proposed. The mold to encrust mutual.inductors with epoxy and mold to inject plastic soapboxes was made with the technique The tooling needs very little time and cost, for the process is only to achieve the nice replica of the prototype. It is benefit for the trial and small batch of production.展开更多
The paper is to outline a new process for manufacturing rapid graphite electrode. It detailsthe steps in Providing integration with Rapid Prototyping (RP) into rapid electrode abrading Process.The key to this combinat...The paper is to outline a new process for manufacturing rapid graphite electrode. It detailsthe steps in Providing integration with Rapid Prototyping (RP) into rapid electrode abrading Process.The key to this combination is the successful model or patted creating using the RP technology.Significantly reduced lead-time, shortened learns curve, lowered revision changes cost and eliminatedor reduced mold polishing are the consequent results. high quality Electrical Discharge Machining(EDM) electrodes are sometimes difficult to be manufactured rapidly and are very time-consumingby conventional methods, even using Computer Numerical Control (CNC) machines. Abradingprovides a simple way to create etuemely detailed and complex electrode to make molds in toolingmaking industries. Integration with the rapid development of the Rapid Prototyping & Manufacturing(RP&M) technology, the rapid electrode abrading process has been regarded as one of the majorbreakthrough in tooling making technology.展开更多
In order to meet the rapid needs of processing square hole in mechanical equipment, the paper expounds the square hole processing method： planetary wheel method, and analyze the principle of tooling structure and pro...In order to meet the rapid needs of processing square hole in mechanical equipment, the paper expounds the square hole processing method： planetary wheel method, and analyze the principle of tooling structure and process with computer graphics parameters design. The results that, as long as the appropriate parameters, using the above method not only can punch the square hole, can also be processed triangle, the five angle and hexagonal regular polygon holes. The square hole processing method can provide theoretical basis and engineering reliable reference for related engineering and technical personnel.展开更多
A rapid wax injection tool of a gearbox shift fork was designed, simulated, and manufactured using rapid prototyping and rapid tooling technology to save time and cost of producing wax models used for the investment c...A rapid wax injection tool of a gearbox shift fork was designed, simulated, and manufactured using rapid prototyping and rapid tooling technology to save time and cost of producing wax models used for the investment casting process. CAE simulation softwares, in particular, MoldFlow, are used to get wax injection moulding parameters such as filling parameters, temperature profiles, freeze time, speed, and pressure. The results of this research were compared with conventional wax model production methods. The criteria of such comparison were based upon parameters such as time, cost, and other related characteristics, which resulted in saving of 50% in time and 60% in cost. In this research, design, assembly, and wax injection operation of the wax tool took 10 days. Considering the fact that wax melting temperature is as low as 70℃ and injection pressure of 0.5 MPa, the tool suffers no damage due to the thermal and pressure stresses, leading to the mass production of wax models.展开更多
While the FAIR Principles do not specify a technical solution for'FAIRness',it was clear from the outset of the FAIR initiative that it would be useful to have commodity software and tooling that would simplif...While the FAIR Principles do not specify a technical solution for'FAIRness',it was clear from the outset of the FAIR initiative that it would be useful to have commodity software and tooling that would simplify the creation of FAIR-compliant resources.The FAIR Data Point is a metadata repository that follows the DCAT(2)schema,and utilizes the Linked Data Platform to manage the hierarchical metadata layers as LDP Containers.There has been a recent flurry of development activity around the FAIR Data Point that has significantly improved its power and ease-of-use.Here we describe five specific tools—an installer,a loader,two Webbased interfaces,and an indexer-aimed at maximizing the uptake and utility of the FAIR Data Point.展开更多
Nickel-based single-crystal superalloy DD98M is widely used in high-temperature components such as aero-engines and gas turbines.Since it has only one crystal grain,the theory of slip deformation along the grain bound...Nickel-based single-crystal superalloy DD98M is widely used in high-temperature components such as aero-engines and gas turbines.Since it has only one crystal grain,the theory of slip deformation along the grain boundary of polycrystalline material is not suitable for the machining of a single crystal part.Therefore,micro-drilling of nickel-based single crystal superalloy still faces problems such as unclear cutting formation me-chanism and unclear surface/subsurface damage mechanism.In this paper,the formation mechanism and morphological characteristics of chips and burrs were studied by a single-factor experiment,and the plastic deformation rule and damage mechanism were investigated,combined with the changes of subsurface structure and grain type.Finally,the influence of the law and reason of tool wear condition on the hole wall and the drilled subsurface is analyzed.The experimental results indicate that drill chips mainly exhibit three morphologies.Their free surfaces feature a serrated appearance,while the contact surfaces are smooth.The entrance burrs are mainly flanging burrs.With the increase of spindle speed,the burr height decreases from 49.38 to 9.39μm.As the feed speed increases,the burr height increases from 6.50 to 63.87μm.The drilled subsurface can be divided into a white layer region,a plastic deformation region,and the matrix according to the microstructural change.As the depth from the machined surface increases,the degree of plastic deformation of the material decreases,the grain size gradually reduces,and the dislocation density decreases.Stacking fault and twinning mostly occur in the high-plastic deformation region,and recrystallization occurs on the machined surface.As the drilling length increases,the degree of tool wear increases,and the adhesion and ablation area on the hole wall surface increase.Moreover,the thickness of the white layer increases from 0 to 8.75μm,and the thickness of the plastic deformation layer increases from 1.28 to 11.31μm.The study has significant theoretical and practical implications for the efficient and low-damage machining of micro-holes in the nickel-based single crystal superalloy.展开更多
Objective expertise evaluation of individuals,as a prerequisite stage for team formation,has been a long-term desideratum in large software development companies.With the rapid advancements in machine learning methods...Objective expertise evaluation of individuals,as a prerequisite stage for team formation,has been a long-term desideratum in large software development companies.With the rapid advancements in machine learning methods,based on reliable existing data stored in project management tools’datasets,automating this evaluation process becomes a natural step forward.In this context,our approach focuses on quantifying software developer expertise by using metadata from the task-tracking systems.For this,we mathematically formalize two categories of expertise:technology-specific expertise,which denotes the skills required for a particular technology,and general expertise,which encapsulates overall knowledge in the software industry.Afterward,we automatically classify the zones of expertise associated with each task a developer has worked on using Bidirectional Encoder Representations from Transformers(BERT)-like transformers to handle the unique characteristics of project tool datasets effectively.Finally,our method evaluates the proficiency of each software specialist across already completed projects from both technology-specific and general perspectives.The method was experimentally validated,yielding promising results.展开更多
Off-axis aspherical mirrors are widely used in optical systems and precision measuring instruments,whereas off-axis aspherical mirrors with large sizes and off-axis are used in large optical systems such as astronomic...Off-axis aspherical mirrors are widely used in optical systems and precision measuring instruments,whereas off-axis aspherical mirrors with large sizes and off-axis are used in large optical systems such as astronomical telescopes and radio telescopes.However,if the off-axis amount of an off-axis aspherical mirror exceeds the capability of the machine tool,traditional rotary-turning machining methods are not applicable,and advanced computerized numerical control(CNC)machining methods,such as the slow-tool-servo method,must be im-plemented.This article proposes a non-conventional offset(NCO)fabrication method based on slow-tool-servo single-point diamond turning for machining off-axis aspherical surfaces with large off-axis amounts.This method is theoretically applicable to the machining of off-axis aspherical surfaces with any off-axis amount.NCO fab-rication is a simpler and more efficient path-planning solution for machining individual off-axis parabolic sur-faces.In addition,corresponding solutions for other types of aspherical surfaces are proposed using the NCO method.The turning depths of workpieces with different off-axis amounts at the same machining position are analyzed and compared.A specific measurement scheme for the NCO method is presented,and the experimental results indicate that the PV and RMS form errors are 0.658μm and 60 nm,respectively.This work demonstrates that the NCO method can effectively deal with the machining challenges of off-axis aspherical structures with large off-axis amounts.展开更多
Introduction:From rules to participation Today,standardization is no longer just about unifying technical terms or setting measurements.It has become a strategic tool to build trust,strengthen competitiveness,and driv...Introduction:From rules to participation Today,standardization is no longer just about unifying technical terms or setting measurements.It has become a strategic tool to build trust,strengthen competitiveness,and drive sustainable economic growth.As industries grow more complex and new technologies and regulations emerge,it is more important than ever to involve all key players:manufacturers,suppliers,consumers,academics,and regulators.Their shared knowledge and input help shape the standards and policies that guide markets,protect consumers,and ensure product quality and safety.展开更多
The surfaces of brittle materials are susceptible to defects such as scratches,cracks,and chipping during con-ventional grinding processes,which significantly compromise surface quality and service performance.A flexi...The surfaces of brittle materials are susceptible to defects such as scratches,cracks,and chipping during con-ventional grinding processes,which significantly compromise surface quality and service performance.A flexible ball-end body-armor-like abrasive tool(BAAT)can effectively remove micro-convex peaks from the surfaces of brittle materials by employing a high tangential grinding force and a low normal grinding force,thereby achieving nano-level surface roughness and ultra-smooth mirror finishes.However,the surface contact me-chanism,pressure distribution pattern,and grinding force behavior between BAAT and workpiece remain in-adequately understood.This study examines the mechanism of liquid film formation and the distribution pattern of elastohydrodynamic pressure in high-shear and low-pressure grinding areas,drawing on the theories of elastohydrodynamic lubrication,non-Newtonian fluid dynamics,and material mechanics.A high-shear low-pressure grinding force model,which incorporates elastohydrodynamic liquid film thickness and abrasive grain size,was developed.The effects of the main grinding parameters(normal load,spindle rotational speed,and abrasive grain size)on the tangential grinding force were investigated through the processing of lithium niobate crystals using an intelligent precision-grinding system.The experimental results indicated that the relative error between the predicted and experimental values was 10.74%,thereby confirming the accuracy of the grinding force model.This study advances the understanding of elastohydrodynamic lubrication mechanisms in abrasive machining and provides a crucial theoretical foundation for the application of flexible ball-end BAAT.展开更多
Alzheimer’s disease(AD)is a complex,progressive neurodegenerative disorder and the leading cause of dementia worldwide.It is characterized by the accumulation of extracellular amyloid-beta(Aβ)plaques and intracellul...Alzheimer’s disease(AD)is a complex,progressive neurodegenerative disorder and the leading cause of dementia worldwide.It is characterized by the accumulation of extracellular amyloid-beta(Aβ)plaques and intracellular tau neurofibrillary tangles,leading to synaptic dysfunction,neuronal loss,and cognitive decline.These pathological changes can begin decades before clinical symptoms emerge,highlighting the critical need for early,accessible,and accurate diagnostic tools.展开更多
Glacial meltwater constitutes a vital component of the water supply in arid and semi-arid areas.However,the influence of glacial melting on runoff and evapotranspiration under global warming remains insufficiently und...Glacial meltwater constitutes a vital component of the water supply in arid and semi-arid areas.However,the influence of glacial melting on runoff and evapotranspiration under global warming remains insufficiently understood.Previous studies coupling the Soil and Water Assessment Tool(SWAT)model with glacier modules often failed to consider the spatial heterogeneity of temperature during glacial melting,potentially leading to biased estimates of meltwater volume.In this study,we developed a glacier-coupled SWAT(SWAT-glacier)model considering the digital elevation model(DEM)based temperature-driven glacial melt processes to elucidate the impact of glacial melting on hydrological processes across four river basins(Dongda,Xiying,Jinta,and Zamu)of the upper Shiyang River Basin(SYRB)in northwestern China from 1986 to 2021.Compared with the standard SWAT model,the proposed SWAT-glacier model significantly improved the simulation accuracy for both runoff and evapotranspiration.Specifically,in comparison with the standard SWAT model,the Nash-Sutcliffe efficiency of the SWAT-glacier model showed a relative improvement of approximately 0.42%–9.16%and 1.50%–10.15%for runoff and evapotranspiration,respectively,in the four river basins during the validation period.Annual glacial runoff occurred predominantly from May to October,whereas glacial melt-induced evapotranspiration peaked between June and August.From 1986 to 2021,the average contributions of glacial melt to runoff were 6.97%for Dongda,3.06%for Xiying,2.70%for Jinta,and 0.67%for Zamu,whereas its contributions to evapotranspiration were 9.06%,5.14%,3.21%,and 1.59%,respectively.This study presents a SWAT-glacier modeling framework that enhances the simulation of hydrological processes in cold regions.The proposed methodology can be extended to other glacierized basins to provide valuable insights into water resource management under climate change.展开更多
Modern manufacturing processes have become more reliant on automation because of the accelerated transition from Industry 3.0 to Industry 4.0.Manual inspection of products on assembly lines remains inefficient,prone t...Modern manufacturing processes have become more reliant on automation because of the accelerated transition from Industry 3.0 to Industry 4.0.Manual inspection of products on assembly lines remains inefficient,prone to errors and lacks consistency,emphasizing the need for a reliable and automated inspection system.Leveraging both object detection and image segmentation approaches,this research proposes a vision-based solution for the detection of various kinds of tools in the toolkit using deep learning(DL)models.Two Intel RealSense D455f depth cameras were arranged in a top down configuration to capture both RGB and depth images of the toolkits.After applying multiple constraints and enhancing them through preprocessing and augmentation,a dataset consisting of 3300 annotated RGB-D photos was generated.Several DL models were selected through a comprehensive assessment of mean Average Precision(mAP),precision-recall equilibrium,inference latency(target≥30 FPS),and computational burden,resulting in a preference for YOLO and Region-based Convolutional Neural Networks(R-CNN)variants over ViT-based models due to the latter’s increased latency and resource requirements.YOLOV5,YOLOV8,YOLOV11,Faster R-CNN,and Mask R-CNN were trained on the annotated dataset and evaluated using key performance metrics(Recall,Accuracy,F1-score,and Precision).YOLOV11 demonstrated balanced excellence with 93.0%precision,89.9%recall,and a 90.6%F1-score in object detection,as well as 96.9%precision,95.3%recall,and a 96.5%F1-score in instance segmentation with an average inference time of 25 ms per frame(≈40 FPS),demonstrating real-time performance.Leveraging these results,a YOLOV11-based windows application was successfully deployed in a real-time assembly line environment,where it accurately processed live video streams to detect and segment tools within toolkits,demonstrating its practical effectiveness in industrial automation.The application is capable of precisely measuring socket dimensions by utilising edge detection techniques on YOLOv11 segmentation masks,in addition to detection and segmentation.This makes it possible to do specification-level quality control right on the assembly line,which improves the ability to examine things in real time.The implementation is a big step forward for intelligent manufacturing in the Industry 4.0 paradigm.It provides a scalable,efficient,and accurate way to do automated inspection and dimensional verification activities.展开更多
文摘Based on the theory of elastic mechanics and material mechanics, the orientation precision of the hohl schaft kegel（HSK） tooling system in static and dynamic states is theoretically and experimentally studied. The relation between the clamping force and the shank taper is obtained. And a proper clamping force is found to be essential to assure the axial and radial orientation precisions of the HSK tooling system in high speed machining （HSM）. Analytical results show that the reason why the HSK tooling system can keep high precision at the high rotational speed is that the actual axial clamping force keeps the two surfaces of the shank and the spindle in contact all the time.
文摘According to the structure of the hohl schaft kegel（HSK） tooling system and its working principle, a mechanical model of the HSK tooling system is established. Major factors influencing the stiffness of the system are analyzed and the relationship between the load and the manufacturing quality is obtained. The basic rule of the stiffness variation is presented and the theoretical analysis is in a good agreement with experimental results. The dynamic stiffness must also be considered to evaluate the performance of the tooling system besides the staticstiffness. Finally, the selecting principles of the HSK types are proposed and their optimum operating conditions are established.
文摘Thermal fatigue and high temperature wear are the two principle failure mechanisms for thixoforming dies. Samples of Inconel 617 and Stellite 6 alloys were submitted to thermal cycling under conditions which approximate thixoforming of steels and to sliding wear tests at 750 ℃. The experimental results thus obtained were compared with those of the X32CrMoV33 hot work tool steel. The Inconel 617 and Stellite 6 samples are much more resistant to oxidation and to softening than the hot work tool steel, providing a superior resistance to thermal fatigue cracking. The wear resistance of the Inconel 617 and Stellite 6 alloys at 750 ℃ is also markedly superior. The adhesive oxides growing slowly on Inconel 617 and Stellite 6 alloys sustain the wear action without spalling and are claimed to be responsible for the superior wear resistance of these alloys at 750 ℃.
文摘The present work compares microstructures of hot work steels made by different processes, that is, by sprayforming,by casting, and a commercially supplied H13 steel. Material benefits are recognized by sprayforming hot working tools such as die inserts for hot forging. The sprayformed hot work steels present a fine and homogeneous microstructure,which implies that, at a similar toughness level, the sprayformed steel can be higher alloyed, so that the thermal fatigue and wear resistance at elevated temperatures can be improved. A series of steels with higher vanadium content than commercial hot work steels are developed. There are no segregation and carbide network problems usually encountered in conventional ingot/forging processed high-vanadium steels. Microstructure and hardness of the new sprayformed steels are studied under different heat treatment conditions. It is justified that these sprayformed steels can be directly used for tooling without high temperature hardening. Sprayforming the tool steels onto a precision ceramic mould is demonstrated to extend the technoeconomical benefits, so that a net shape production tool can be rapidly made.Features of the rapid tooling process are also discussed.
基金University of Liège,Walloon Region (First Europe Program Convention n°"NEP" 415824,THIXALU Project and MAGAL Project) and the COST 541 for their financial support
文摘Thixoforging is a type of semi-solid metal processing at high solid fraction (0.7<φs<1), which involves the processing of alloys in the semi-solid state.Tooling has to be adapted to this particular process to benefit shear thinning and thixotropic behaviour of such semi-solid material.Tooling parameters, such as the forming speed and tool temperature, have to be accurately controlled because of their influence on thermal exchanges between material flow and tool.These thermal exchanges influence the high-cracking tendency and the rheology of the semi-solid material during forming, which affects parts properties and therefore their quality.Extrusion tests show how thermal exchanges influence quality of thixoforged parts made of 7075 aluminium alloys at high solid fraction by modifying process parameters like forming speed, tool temperature and tool thermal protector.Thus an optimum in terms of thermal exchanges has to be found between surface quality and mechanical properties of the part.A direct application is the evaluation of surface quality of thixoforged thin wall parts made of 7075 aluminium alloy.
文摘X32CrMoV33 hot work tool steel samples coated with AlTiN and AlTiON were submitted to thermal cycling under conditions that approximate thixoforming of steels and to sliding wear tests at 750 ℃,measured to be the cavity surface temperature shortly after the steel slurry is forced into the thixoforming die.AlTiN and AlTiON coatings provide adequate protection against oxidation of the tool steel substrate,but fail to avoid thermal fatigue cracking.This is attributed to the extensive softening of the substrate,the thermal expansion mismatch between the hot work tool steel and the coatings and residual compressive stresses inherited from the deposition process.The impact of AlTiN and AlTiON coatings on the high temperature wear resistance,on the other hand,is favourable.The improved wear resistance is attributed to the stable,protective surface oxide films.
文摘Rapid tooling technique based on the sterelithograph prototype is investigated. The epoxy tooling technological process was elucidated. It is analyzed in detail that the epoxy resin formula is easy to cast, curing process, and release agents. The transitional plaster model is also proposed. The mold to encrust mutual.inductors with epoxy and mold to inject plastic soapboxes was made with the technique The tooling needs very little time and cost, for the process is only to achieve the nice replica of the prototype. It is benefit for the trial and small batch of production.
文摘The paper is to outline a new process for manufacturing rapid graphite electrode. It detailsthe steps in Providing integration with Rapid Prototyping (RP) into rapid electrode abrading Process.The key to this combination is the successful model or patted creating using the RP technology.Significantly reduced lead-time, shortened learns curve, lowered revision changes cost and eliminatedor reduced mold polishing are the consequent results. high quality Electrical Discharge Machining(EDM) electrodes are sometimes difficult to be manufactured rapidly and are very time-consumingby conventional methods, even using Computer Numerical Control (CNC) machines. Abradingprovides a simple way to create etuemely detailed and complex electrode to make molds in toolingmaking industries. Integration with the rapid development of the Rapid Prototyping & Manufacturing(RP&M) technology, the rapid electrode abrading process has been regarded as one of the majorbreakthrough in tooling making technology.
文摘In order to meet the rapid needs of processing square hole in mechanical equipment, the paper expounds the square hole processing method： planetary wheel method, and analyze the principle of tooling structure and process with computer graphics parameters design. The results that, as long as the appropriate parameters, using the above method not only can punch the square hole, can also be processed triangle, the five angle and hexagonal regular polygon holes. The square hole processing method can provide theoretical basis and engineering reliable reference for related engineering and technical personnel.
基金the Rapid Prototyping & Tool-ing Branch of SAPCO Part Supplier of Car Manufacturing Co. of Iran-Khodro and POULADIR Investment Casting Company for supporting this project
文摘A rapid wax injection tool of a gearbox shift fork was designed, simulated, and manufactured using rapid prototyping and rapid tooling technology to save time and cost of producing wax models used for the investment casting process. CAE simulation softwares, in particular, MoldFlow, are used to get wax injection moulding parameters such as filling parameters, temperature profiles, freeze time, speed, and pressure. The results of this research were compared with conventional wax model production methods. The criteria of such comparison were based upon parameters such as time, cost, and other related characteristics, which resulted in saving of 50% in time and 60% in cost. In this research, design, assembly, and wax injection operation of the wax tool took 10 days. Considering the fact that wax melting temperature is as low as 70℃ and injection pressure of 0.5 MPa, the tool suffers no damage due to the thermal and pressure stresses, leading to the mass production of wax models.
基金supported by Czech Technical University in Prague grant No.SGS20/209/OHK3/3T/18.LOBSS,RK and KB are partially funded by funding from the Horizon2020 projects FAIRsFAIR grant No.831558.
文摘While the FAIR Principles do not specify a technical solution for'FAIRness',it was clear from the outset of the FAIR initiative that it would be useful to have commodity software and tooling that would simplify the creation of FAIR-compliant resources.The FAIR Data Point is a metadata repository that follows the DCAT(2)schema,and utilizes the Linked Data Platform to manage the hierarchical metadata layers as LDP Containers.There has been a recent flurry of development activity around the FAIR Data Point that has significantly improved its power and ease-of-use.Here we describe five specific tools—an installer,a loader,two Webbased interfaces,and an indexer-aimed at maximizing the uptake and utility of the FAIR Data Point.
基金Supported by National Natural Science Foundation of China(Grant Nos.52475433,52305453)Hebei Provincial Natural Science Foundation(Grant No.E2022501004)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2023GFYD002)Shijiazhuang Municipal Science and Technology Plan Project(Grant No.241790747A).
文摘Nickel-based single-crystal superalloy DD98M is widely used in high-temperature components such as aero-engines and gas turbines.Since it has only one crystal grain,the theory of slip deformation along the grain boundary of polycrystalline material is not suitable for the machining of a single crystal part.Therefore,micro-drilling of nickel-based single crystal superalloy still faces problems such as unclear cutting formation me-chanism and unclear surface/subsurface damage mechanism.In this paper,the formation mechanism and morphological characteristics of chips and burrs were studied by a single-factor experiment,and the plastic deformation rule and damage mechanism were investigated,combined with the changes of subsurface structure and grain type.Finally,the influence of the law and reason of tool wear condition on the hole wall and the drilled subsurface is analyzed.The experimental results indicate that drill chips mainly exhibit three morphologies.Their free surfaces feature a serrated appearance,while the contact surfaces are smooth.The entrance burrs are mainly flanging burrs.With the increase of spindle speed,the burr height decreases from 49.38 to 9.39μm.As the feed speed increases,the burr height increases from 6.50 to 63.87μm.The drilled subsurface can be divided into a white layer region,a plastic deformation region,and the matrix according to the microstructural change.As the depth from the machined surface increases,the degree of plastic deformation of the material decreases,the grain size gradually reduces,and the dislocation density decreases.Stacking fault and twinning mostly occur in the high-plastic deformation region,and recrystallization occurs on the machined surface.As the drilling length increases,the degree of tool wear increases,and the adhesion and ablation area on the hole wall surface increase.Moreover,the thickness of the white layer increases from 0 to 8.75μm,and the thickness of the plastic deformation layer increases from 1.28 to 11.31μm.The study has significant theoretical and practical implications for the efficient and low-damage machining of micro-holes in the nickel-based single crystal superalloy.
基金supported by the project“Romanian Hub for Artificial Intelligence-HRIA”,Smart Growth,Digitization and Financial Instruments Program,2021–2027,MySMIS No.334906.
文摘Objective expertise evaluation of individuals,as a prerequisite stage for team formation,has been a long-term desideratum in large software development companies.With the rapid advancements in machine learning methods,based on reliable existing data stored in project management tools’datasets,automating this evaluation process becomes a natural step forward.In this context,our approach focuses on quantifying software developer expertise by using metadata from the task-tracking systems.For this,we mathematically formalize two categories of expertise:technology-specific expertise,which denotes the skills required for a particular technology,and general expertise,which encapsulates overall knowledge in the software industry.Afterward,we automatically classify the zones of expertise associated with each task a developer has worked on using Bidirectional Encoder Representations from Transformers(BERT)-like transformers to handle the unique characteristics of project tool datasets effectively.Finally,our method evaluates the proficiency of each software specialist across already completed projects from both technology-specific and general perspectives.The method was experimentally validated,yielding promising results.
基金Supported by National Key R&D Program of China(Grant No.2023YFE0203800)the National Natural Science Foundation of China(Grant No.52105482).
文摘Off-axis aspherical mirrors are widely used in optical systems and precision measuring instruments,whereas off-axis aspherical mirrors with large sizes and off-axis are used in large optical systems such as astronomical telescopes and radio telescopes.However,if the off-axis amount of an off-axis aspherical mirror exceeds the capability of the machine tool,traditional rotary-turning machining methods are not applicable,and advanced computerized numerical control(CNC)machining methods,such as the slow-tool-servo method,must be im-plemented.This article proposes a non-conventional offset(NCO)fabrication method based on slow-tool-servo single-point diamond turning for machining off-axis aspherical surfaces with large off-axis amounts.This method is theoretically applicable to the machining of off-axis aspherical surfaces with any off-axis amount.NCO fab-rication is a simpler and more efficient path-planning solution for machining individual off-axis parabolic sur-faces.In addition,corresponding solutions for other types of aspherical surfaces are proposed using the NCO method.The turning depths of workpieces with different off-axis amounts at the same machining position are analyzed and compared.A specific measurement scheme for the NCO method is presented,and the experimental results indicate that the PV and RMS form errors are 0.658μm and 60 nm,respectively.This work demonstrates that the NCO method can effectively deal with the machining challenges of off-axis aspherical structures with large off-axis amounts.
文摘Introduction:From rules to participation Today,standardization is no longer just about unifying technical terms or setting measurements.It has become a strategic tool to build trust,strengthen competitiveness,and drive sustainable economic growth.As industries grow more complex and new technologies and regulations emerge,it is more important than ever to involve all key players:manufacturers,suppliers,consumers,academics,and regulators.Their shared knowledge and input help shape the standards and policies that guide markets,protect consumers,and ensure product quality and safety.
基金Supported by National Natural Science Foundation of China(Grant Nos.52575516,51875329)Taishan Scholar Special Foundation of Shandong Province(Grant Nos.tstp20240826,tsqn201812064)+2 种基金Shandong Provincial Natural Science Foundation(Grant No.ZR2023ME112)Key Research and Development Project of the Ningxia Hui Autonomous Region(Grant No.2024BEE02019)Innovation Capacity Improvement Programme for High-tech SMEs of Shandong Province(Grant Nos.2022TSGC1333,2022TSGC1261).
文摘The surfaces of brittle materials are susceptible to defects such as scratches,cracks,and chipping during con-ventional grinding processes,which significantly compromise surface quality and service performance.A flexible ball-end body-armor-like abrasive tool(BAAT)can effectively remove micro-convex peaks from the surfaces of brittle materials by employing a high tangential grinding force and a low normal grinding force,thereby achieving nano-level surface roughness and ultra-smooth mirror finishes.However,the surface contact me-chanism,pressure distribution pattern,and grinding force behavior between BAAT and workpiece remain in-adequately understood.This study examines the mechanism of liquid film formation and the distribution pattern of elastohydrodynamic pressure in high-shear and low-pressure grinding areas,drawing on the theories of elastohydrodynamic lubrication,non-Newtonian fluid dynamics,and material mechanics.A high-shear low-pressure grinding force model,which incorporates elastohydrodynamic liquid film thickness and abrasive grain size,was developed.The effects of the main grinding parameters(normal load,spindle rotational speed,and abrasive grain size)on the tangential grinding force were investigated through the processing of lithium niobate crystals using an intelligent precision-grinding system.The experimental results indicated that the relative error between the predicted and experimental values was 10.74%,thereby confirming the accuracy of the grinding force model.This study advances the understanding of elastohydrodynamic lubrication mechanisms in abrasive machining and provides a crucial theoretical foundation for the application of flexible ball-end BAAT.
文摘Alzheimer’s disease(AD)is a complex,progressive neurodegenerative disorder and the leading cause of dementia worldwide.It is characterized by the accumulation of extracellular amyloid-beta(Aβ)plaques and intracellular tau neurofibrillary tangles,leading to synaptic dysfunction,neuronal loss,and cognitive decline.These pathological changes can begin decades before clinical symptoms emerge,highlighting the critical need for early,accessible,and accurate diagnostic tools.
基金supported by the National Key Research and Development Program of China(2022YFD1900501)the Gansu Provincial Water Conservancy Scientific Experimental Research and Technology Extension Project(25GSLK044,26GSLK093).
文摘Glacial meltwater constitutes a vital component of the water supply in arid and semi-arid areas.However,the influence of glacial melting on runoff and evapotranspiration under global warming remains insufficiently understood.Previous studies coupling the Soil and Water Assessment Tool(SWAT)model with glacier modules often failed to consider the spatial heterogeneity of temperature during glacial melting,potentially leading to biased estimates of meltwater volume.In this study,we developed a glacier-coupled SWAT(SWAT-glacier)model considering the digital elevation model(DEM)based temperature-driven glacial melt processes to elucidate the impact of glacial melting on hydrological processes across four river basins(Dongda,Xiying,Jinta,and Zamu)of the upper Shiyang River Basin(SYRB)in northwestern China from 1986 to 2021.Compared with the standard SWAT model,the proposed SWAT-glacier model significantly improved the simulation accuracy for both runoff and evapotranspiration.Specifically,in comparison with the standard SWAT model,the Nash-Sutcliffe efficiency of the SWAT-glacier model showed a relative improvement of approximately 0.42%–9.16%and 1.50%–10.15%for runoff and evapotranspiration,respectively,in the four river basins during the validation period.Annual glacial runoff occurred predominantly from May to October,whereas glacial melt-induced evapotranspiration peaked between June and August.From 1986 to 2021,the average contributions of glacial melt to runoff were 6.97%for Dongda,3.06%for Xiying,2.70%for Jinta,and 0.67%for Zamu,whereas its contributions to evapotranspiration were 9.06%,5.14%,3.21%,and 1.59%,respectively.This study presents a SWAT-glacier modeling framework that enhances the simulation of hydrological processes in cold regions.The proposed methodology can be extended to other glacierized basins to provide valuable insights into water resource management under climate change.
文摘Modern manufacturing processes have become more reliant on automation because of the accelerated transition from Industry 3.0 to Industry 4.0.Manual inspection of products on assembly lines remains inefficient,prone to errors and lacks consistency,emphasizing the need for a reliable and automated inspection system.Leveraging both object detection and image segmentation approaches,this research proposes a vision-based solution for the detection of various kinds of tools in the toolkit using deep learning(DL)models.Two Intel RealSense D455f depth cameras were arranged in a top down configuration to capture both RGB and depth images of the toolkits.After applying multiple constraints and enhancing them through preprocessing and augmentation,a dataset consisting of 3300 annotated RGB-D photos was generated.Several DL models were selected through a comprehensive assessment of mean Average Precision(mAP),precision-recall equilibrium,inference latency(target≥30 FPS),and computational burden,resulting in a preference for YOLO and Region-based Convolutional Neural Networks(R-CNN)variants over ViT-based models due to the latter’s increased latency and resource requirements.YOLOV5,YOLOV8,YOLOV11,Faster R-CNN,and Mask R-CNN were trained on the annotated dataset and evaluated using key performance metrics(Recall,Accuracy,F1-score,and Precision).YOLOV11 demonstrated balanced excellence with 93.0%precision,89.9%recall,and a 90.6%F1-score in object detection,as well as 96.9%precision,95.3%recall,and a 96.5%F1-score in instance segmentation with an average inference time of 25 ms per frame(≈40 FPS),demonstrating real-time performance.Leveraging these results,a YOLOV11-based windows application was successfully deployed in a real-time assembly line environment,where it accurately processed live video streams to detect and segment tools within toolkits,demonstrating its practical effectiveness in industrial automation.The application is capable of precisely measuring socket dimensions by utilising edge detection techniques on YOLOv11 segmentation masks,in addition to detection and segmentation.This makes it possible to do specification-level quality control right on the assembly line,which improves the ability to examine things in real time.The implementation is a big step forward for intelligent manufacturing in the Industry 4.0 paradigm.It provides a scalable,efficient,and accurate way to do automated inspection and dimensional verification activities.
