This paper aims at reporting the results of a number of drag pick cutting tests on selected igneous rock samples to compare the experimentally determined maximum cutting force （FC） values with theoreti- cally estima...This paper aims at reporting the results of a number of drag pick cutting tests on selected igneous rock samples to compare the experimentally determined maximum cutting force （FC） values with theoreti- cally estimated ones. First, a review on theoretical rock cutting models proposed for both chisel and conical picks was presented in detail. Experimental study consists of both chisel and conical pick cutting tests in unrelieved （single-pick） cutting mode with varying cutting depths. FC＇ values were determined from experimental results, and theoretical models were utilized to compute FC for all cutting conditions. Computed and experimentally determined F（ data were then compared for a referenced cutting depth. It is shown that the theoretical models might overestimate or underestimate FC＇ and cannot give reliable results. Finally, explanations for these mismatches were presented.展开更多
With the widespread adoption of ultra-precision machining(UPM)in manufacturing,accurately monitoring the temperature within micro-scale cutting zones has become crucial for ensuring machining quality and tool longevit...With the widespread adoption of ultra-precision machining(UPM)in manufacturing,accurately monitoring the temperature within micro-scale cutting zones has become crucial for ensuring machining quality and tool longevity.This review comprehensively evaluates modern in-process cutting temperature measurement methods,comparing conventional approaches and emerging technologies.Thermal conduction-based and radiation-based measurement paradigms are analyzed in terms of their merits,limitations,and domain-specific applicability,particularly with regard to the unique challenges involving micro-scale cutting zones in UPM.Special emphasis is placed on micro-scale sensor-integrated tools and self-sensing tools that enable real-time thermal monitoring at cutting edges.Furthermore,we explore thermal monitoring and management techniques for atomic and close-to-atomic scale manufacturing(ACSM),as well as the transformative potential of emerging technologies like artificial intelligence(AI),internet of things(IoT),and data fusion for machining temperature measurement.This review may serve as a reference for UPM cutting temperature measurement research,helping foster the development of optimized process control technologies.展开更多
Through systematic cutting experiments, characteristics of the cutting performance of Ti(C, N) based cermets is identified. The experiments were designed to study their resistance,toughness, cutting force, tool-chip f...Through systematic cutting experiments, characteristics of the cutting performance of Ti(C, N) based cermets is identified. The experiments were designed to study their resistance,toughness, cutting force, tool-chip friction coefficient and machining quality by comparing them with those of WC based cemented carbides. The cutting data and the regressed empirical formulae would be useful to promote proper application of cermet cutting tool materials.展开更多
The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and med...The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry.展开更多
At present, most commercial computer-aided manufacturing （CAM） systems are deficient in efficiency and performances on generating tool path during machining impellers. To solve the problem, this article develops a s...At present, most commercial computer-aided manufacturing （CAM） systems are deficient in efficiency and performances on generating tool path during machining impellers. To solve the problem, this article develops a special software to plan cutting path for ruled surface impellers. An approximation algorithm to generate cutting path for machining integral ruled surface impellers is proposed. By fitting sampling data points of an impeller blade into a curve, a model of ruled surface blade of an impeller is built up. Furthermore, by calculating the points where the cutter axis vector intersects the free-form hub surface of an impeller, problems about, for instance, the ambiguity in calculation and machining the wide blade surface with a short flute cutter are solved. Finally, an integral impeller cutting path is planned by way of an integrated cutter location control algorithm. Simulation and machining tests with an impeller are performed on a 5-axis computer numerically controlled （CNC） mill machine, which shows the feasibility of the proposed algorithm.展开更多
In machining the particle reinforced aluminum based composite material with high Si content using the cobalt-cemented tungsten carbide micro cutting tools, diamond like carbon （DLC） films are deposited on cobalt-cem...In machining the particle reinforced aluminum based composite material with high Si content using the cobalt-cemented tungsten carbide micro cutting tools, diamond like carbon （DLC） films are deposited on cobalt-cemented tungsten carbide micro-drills with two-step pretreatment method. Characteristics of DLC coated tools are investigated in bias-enhanced HFCVD system with the optimized hot filament arrangement. The optimization deposition technology is obtained and the wear mechanism of cutting tools is analyzed. The drilling performance of DLC coated tools is verified by the experiments of cutting particle reinforced aluminum based composite material （Si 15% in volume） compared with uncoated ones. Experimental results show that the two-step pretreatment method is appropriate for complex shaped cemented carbide substrates and ensures the good adhesive strength between the diamond film and the substrate. The cutting performance of DLC coated tool is enhanced 10 times when machining the Si particle reinforced aluminum based metal matrix composite compared with that of uncoated ones under the same cutting conditions.展开更多
China has a history of more than five thousand years,and its culture is broad and rich.Among many traditional arts,paper-cutting is a special handicraft full of stories and myths.Paper-cutting is a unique art.People u...China has a history of more than five thousand years,and its culture is broad and rich.Among many traditional arts,paper-cutting is a special handicraft full of stories and myths.Paper-cutting is a unique art.People use scissors to cut paper into many beautiful shapes,such as flowers,animals,or people.This art only needs simple tools,but it is not as easy as it looks.When we watch the masters cut paper,they can create wonderful patterns in just a few minutes.However,for beginners,a lot of practice and patience are necessary.展开更多
A centrifugal pump with a specific speed ns=67 is considered in this study to investigate the impact of blade cutting(at the outlet edge)on the fluid-induced noise,while keeping all the other geometric parameters unch...A centrifugal pump with a specific speed ns=67 is considered in this study to investigate the impact of blade cutting(at the outlet edge)on the fluid-induced noise,while keeping all the other geometric parameters unchanged.The required unsteady numerical calculations are conducted by applying the RNG k-εturbulence model with the volute dipole being used as the sound source.The results indicate that the internal pressure energy of the centrifugal pump essentially depends on the blade passing frequency and its low-frequency harmonic frequency.Moreover,the pressure pulsation distribution directly affects the noise caused by the centrifugal pump.The sound pressure inside and outside the centrifugal pump and the sound power at the blade passing frequency gradually decrease increasing cutting distance of the impeller blades.When the cutting percentage is 1.21%,that is,the clearance ratio between impeller blade and tongue is 8.57%,the comprehensive performance of the centrifugal pump is the best.展开更多
Have we ever seen such a shocking garment in the fashion industry?A down jacket that claims to be one but uses absolutely no down,yet possesses remarkable heating and insulating properties,all designed with a colorles...Have we ever seen such a shocking garment in the fashion industry?A down jacket that claims to be one but uses absolutely no down,yet possesses remarkable heating and insulating properties,all designed with a colorless aesthetic.It resembles clothing that has come from the future.The secret behind this captivating design lies in"SOLAMENTR■"developed by Sumitomo Metal Mining Co.,Ltd.展开更多
To meet the demand for the machining of blisks with narrow cascade channels and twisted blade profiles,especially integral shrouded blisks with shrouds,this paper innovatively proposes a method for dynamic deformation...To meet the demand for the machining of blisks with narrow cascade channels and twisted blade profiles,especially integral shrouded blisks with shrouds,this paper innovatively proposes a method for dynamic deformation electrochemical cutting of flexible electrodes with arrayed group slit structure.By applying torque to both ends of the flexible electrode,the proposed method produces bending deformation and realizes the processing of a twisted profile.The flexible electrode is an important carrier of this method,and its properties such as elasticity,rigidity,and flow field uniformity have a crucial impact on smooth processing.Therefore,this paper proposes a design theory of flexible electrodes with an arrayed group slit structure and designs flexible electrodes with variable cross-sections.Compared with traditional uniform section tube electrode,the designed flexible electrode was subjected to the corresponding mechanical simulation,flow field simulation,and fluid–structure interaction simulation to investigate the elasticity,rigidity,and flow field uniformity of the flexible electrode.In addition,a deformation device of flexible electrodes was constructed and the corresponding experiments were carried out.Simulations and experiments demonstrate that flexible electrodes with arrayed group slit structures have good comprehensive performance.Finally,typical components were successfully machined to verify the feasibility of the proposed method and the rationality of the designed flexible electrode.It is shown that the proposed method has great potential for the machining of distorted profiles and provides a new idea for the machining of complex profiles.展开更多
Real-time identification of rock strength and cuttability based on monitoring while cutting during excavation is essential for key procedures such as the precise adjustment of excavation parameters and the in-situ mod...Real-time identification of rock strength and cuttability based on monitoring while cutting during excavation is essential for key procedures such as the precise adjustment of excavation parameters and the in-situ modification of hard rocks.This study proposes an in-telligent approach for predicting rock strength and cuttability.A database comprising 132 data sets is established,containing cutting para-meters(such as cutting depth and pick angle),cutting responses(such as specific energy and instantaneous cutting rate),and rock mech-anical parameters collected from conical pick-cutting experiments.These parameters serve as input features for predicting the uniaxial compressive strength and tensile strength of rocks using regression fitting and machine learning methodologies.In addition,rock cuttabil-ity is classified using a combination of the analytic hierarchy process and fuzzy comprehensive evaluation method,and subsequently iden-tified through machine learning approaches.Various models are compared to determine the optimal predictive and classification models.The results indicate that the optimal model for uniaxial compressive strength and tensile strength prediction is the genetic algorithm-optimized backpropagation neural network model,and the optimal model for rock cuttability classification is the radial basis neural network model.展开更多
The water conductivity of karst collapsed column is affected by multiple factors such as the characteristics of its own column filling,structure and mining disturbance.As a structural water-conducting channel,fault us...The water conductivity of karst collapsed column is affected by multiple factors such as the characteristics of its own column filling,structure and mining disturbance.As a structural water-conducting channel,fault usually plays a controlling role in hydrogeological structure.During the process of mine water hazard prevention and control,it was discovered that the lithology composition,compaction and cementation degree and water physical properties of karst collapsed column fillings were all non-conducting water,but due to the influence of combined development faults,some exploration drill holes showed concentrated water outflow.Based on this,the scientific hypothesis was proposed that fault cutting leads to water conduction in karst collapsed columns.The study comprehensively used methods like chronology,exploration data analysis,and hydrochemical testing to analyze the chronological relationship between faults and karst collapsed columns,their spatial relationship,outlet point distribution and water chemical properties,and the impact of faults on the water-conductivity of karst collapsed columns,which proved the effect of fault cutting on changing water conductivity of karst collapsed column.The research showed that later fault cutting through karst collapsed columns turned the originally non-conductive karst collapsed columns into water-conductive collapsed columns at the fault plane,creating a longitudinally connected water-conducting channel.A new model of fault cutting karst collapsed column to change the original water conductivity of karst collapsed column was proposed.The research results can provide a theoretical basis for the prediction of the water conductivity of the karst collapsed column.According to whether the karst collapsed column was cut by the fault,it was predicted theoretically,so as to determine the key areas of water conductivity detection and prevention and control,and has broad application prospects under the background of source control of mine water disaster.展开更多
During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological envir...During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological environment,abrasive jets cannot fully utilize their rock-cutting performance.To fully exploit the advantages of high-pressure abrasive water jets,five orthogonal experiments were designed for rocks with significant differences in strength.Experimental research has been conducted on the performance of rotating abrasive waterjet-cutting rocks.Moreover,a neural network prediction model for predicting rock-cutting characteristics is established by comprehensively considering rock mechanics parameters and abrasive water jet parameters.The results show that the cutting depth of rocks with different strengths increases nonlinearly with increasing work pressure of the abrasive water jet.The cutting depth decreases exponentially with increasing cutting velocity.The cutting depth first increases and then decreases with increasing target distance,and the best target distance is between 4 mm and 6 mm.The effect of the target distance on the cutting width of rock is the most significant,but the cutting width of high-strength rock is not sensitive to changes in the working parameters of the abrasive water jet.The average relative errors of BP(backpropagation)neural networks optimized by global optimization algorithms in predicting rock cutting depth and width are 13.3%and 5.4%,respectively.This research combines the working characteristics of mining machinery to study the performance of abrasive waterjet rotary cutting of rocks and constructs a predictive model for the performance of abrasive waterjet cutting of rocks that includes rock strength factors.This provides a new solution for quickly adjusting the working parameters of abrasive water jets according to mining conditions.展开更多
Shanghai is blazing a new development track powered by dual engines:one is intelligent manufacturing empowered by cutting-edge technologies,and the other is green development driven by low-carbon and energy-saving sol...Shanghai is blazing a new development track powered by dual engines:one is intelligent manufacturing empowered by cutting-edge technologies,and the other is green development driven by low-carbon and energy-saving solutions.On September 10,China Today visited two enterprises in Shanghai-Shanghai Schneider Electric Industrial Control Co.,Ltd.and Huaqin Technology Co.,Ltd.-to observe firsthand how global investment and local innovation are jointly shaping Shanghai’s future of high-quality development.展开更多
The fatigue resistance of casting polyurethane(CPU)is crucial in various sectors,such as construction,healthcare,and the automotive industry.Despite its importance,no studies have reported on the fatigue threshold of ...The fatigue resistance of casting polyurethane(CPU)is crucial in various sectors,such as construction,healthcare,and the automotive industry.Despite its importance,no studies have reported on the fatigue threshold of CPU.This study employed an advanced Intrinsic Strength Analyzer(ISA)to evaluate the fatigue threshold of CPUs,systematically exploring the effects of three types of isocyanates(PPDI,NDI,TDI)that contribute to hard segment structures based on the cutting method.Employing multiple advanced characterization techniques(XRD,TEM,DSC,AFM),the results indicate that PPDI-based polyurethane exhibits the highest fatigue threshold(182.89 J/m^(2))due to a highest phase separation and a densely packed spherulitic structure,although the hydrogen bonding degree is the lowest(48.3%).Conversely,NDI-based polyurethane,despite having the high hydrogen bonding degree(53.6%),exhibits moderate fatigue performance(122.52 J/m^(2)),likely due to a more scattered microstructure.TDI-based polyurethane,with the highest hydrogen bonding degree(59.1%)but absence of spherulitic structure,shows the lowest fatigue threshold(46.43 J/m^(2)).Compared to common rubbers(NR,NBR,EPDM,BR),the superior fatigue performance of CPU is attributed to its well-organized microstructure,polyurethane possesses a higher fatigue threshold due to its high phase separation degree and orderly and dense spherulitic structure which enhances energy dissipation and reduces crack propagation.展开更多
Vibration cutting has emerged as a promising method for creating surface functional microstructures.However,achieving precise tool setting is a time-consuming process that significantly impacts process efficiency.This...Vibration cutting has emerged as a promising method for creating surface functional microstructures.However,achieving precise tool setting is a time-consuming process that significantly impacts process efficiency.This study proposes an intelligent approach for tool setting in vibration cutting using machine vision and hearing,divided into two steps.In the first step,machine vision is employed to achieve rough precision in tool setting within tens of micrometers.Subsequently,in the second step,machine hearing utilizes sound pickup to capture vibration audio signals,enabling fine tool adjustment within 1μm precision.The relationship between the spectral intensity of vibration audio and cutting depth is analyzed to establish criteria for tool–workpiece contact.Finally,the efficacy of this approach is validated on an ultra-precision platform,demonstrating that the automated tool-setting process takes no more than 74 s.The total cost of the vision and hearing sensors is less than$1500.展开更多
The 3rd China International Supply Chain Expo(hereinafter referred to as the CISCE)is approaching,and NEXWISE Intelligence China Limited(hereinaf ter refer red to as NEXWISE Intelligence),a repeat exhibitor at the eve...The 3rd China International Supply Chain Expo(hereinafter referred to as the CISCE)is approaching,and NEXWISE Intelligence China Limited(hereinaf ter refer red to as NEXWISE Intelligence),a repeat exhibitor at the event,is ready for the show.In the E4 Hall’s Digital Technology Exhibition Zone,this AI-focused company will showcase its two flagship products and technology systems:“Zhang An Xing”Smart Security and“KuberAI(Producer Platform)”Computing Power Foundation,demonstrating China’s innovative AIdriven efforts in empowering industrial chain security.展开更多
Cardiovascular disease is the leading cause of human mortality,and calcified tissue blocking blood vessels is the main cause of major adverse cardiovascular events(MACE).Rotational Atherectomy(RA)is a minimally invasi...Cardiovascular disease is the leading cause of human mortality,and calcified tissue blocking blood vessels is the main cause of major adverse cardiovascular events(MACE).Rotational Atherectomy(RA)is a minimally invasive catheterbased treatment method that involves high-speed cutting of calcified tissue using miniature tools for removal.However,the cutting forces,heat,and debris can induce tissue damage and give rise to serious surgical complications.To enhance the effectiveness and efficiency of RA,a novel eccentric rotational cutting tool,with one side comprising axial and circumferential staggered micro-blades,was designed and fabricated in this study.In addition,a series of experiments were conducted to analyze their performance across five dimensions:tool kinematics,force,temperature,debris,and surface morphology of the specimens.Experimental results show that the force,temperature and debris size of the novel tool were well inhibited at the highest rotational speed.For the tool of standard clinical size(diameter 1.25 mm),the maximum force is 0.75 N,with a maximum temperature rise in the operation area of 1.09℃.Debris distribution followed a normal distribution pattern,with 90%of debris measuring smaller than 9.12μm.All tool metrics met clinical safety requirements,indicating its superior performance.This study provides a new idea for the design of calcified tissue removal tools,and contributes positively to the advancement of RA.展开更多
High-speed milling(HSM)is advantageous for machining high-quality complex-structure surface components with various materials.Identifying and estimating cutting force signals for characterizing HSM is of high signific...High-speed milling(HSM)is advantageous for machining high-quality complex-structure surface components with various materials.Identifying and estimating cutting force signals for characterizing HSM is of high significance.However,considering the tool runout and size effects,many proposed models focus on the material and mechanical characteristics.This study presents a novel approach for predicting micromilling cutting forces using a semianalytical multidimensional model that integrates experimental empirical data and a mechanical theoretical force model.A novel analytical optimization approach is provided to identify the cutting forces,classify the cutting states,and determine the tool runout using an adaptive algorithm that simplifies modeling and calculation.The instantaneous un-deformed chip thickness(IUCT)is determined from the trochoidal trajectories of each tool flute and optimized using the bisection method.Herein,the computational efficiency is improved,and the errors are clarified.The tool runout parameters are identified from the processed displacement signals and determined from the preprocessed vibration signals using an adaptive signal processing method.It is reliable and stable for determining tool runout and is an effective foundation for the force model.This approach is verified using HSM tests.Herein,the determination coefficients are stable above 0.9.It is convenient and efficient for achieving the key intermediate parameters(IUCT and tool runout),which can be generalized to various machining conditions and operations.展开更多
To address the issue of uneven temperature distribution in shale gas oil-based drill cuttings pyrolysis furnaces,a numerical model was developed using Fluent software.The effects of nitrogen flow rate,heating tube spa...To address the issue of uneven temperature distribution in shale gas oil-based drill cuttings pyrolysis furnaces,a numerical model was developed using Fluent software.The effects of nitrogen flow rate,heating tube spacing,and furnace dimensions on the internal temperature field were thoroughly analyzed from a mechanistic perspective.The results indicated that non-uniform radiation from the heating tubes and flow disturbances induced by the nitrogen stream were the primary causes of localized heat concentration.Under no-load conditions,the maximum deviation between simulated and on-site measured temperatures was 1.5%,validating the model’s accuracy.Further-more,this study investigated the trade-offs between temperature uniformity,energy consumption,and construction costs.The findings provide a crucial design basis and a reliable simulation platform for developing and optimizing pyrolysis equipment.展开更多
文摘This paper aims at reporting the results of a number of drag pick cutting tests on selected igneous rock samples to compare the experimentally determined maximum cutting force （FC） values with theoreti- cally estimated ones. First, a review on theoretical rock cutting models proposed for both chisel and conical picks was presented in detail. Experimental study consists of both chisel and conical pick cutting tests in unrelieved （single-pick） cutting mode with varying cutting depths. FC＇ values were determined from experimental results, and theoretical models were utilized to compute FC for all cutting conditions. Computed and experimentally determined F（ data were then compared for a referenced cutting depth. It is shown that the theoretical models might overestimate or underestimate FC＇ and cannot give reliable results. Finally, explanations for these mismatches were presented.
基金supported by the National Natural Science Foundation of China(Nos.52425505 and U22A20207)the National Key R&D Program of China(No.2022YFB3403302)the Zhejiang Provincial Key R&D Program of China(No.2023C01056).
文摘With the widespread adoption of ultra-precision machining(UPM)in manufacturing,accurately monitoring the temperature within micro-scale cutting zones has become crucial for ensuring machining quality and tool longevity.This review comprehensively evaluates modern in-process cutting temperature measurement methods,comparing conventional approaches and emerging technologies.Thermal conduction-based and radiation-based measurement paradigms are analyzed in terms of their merits,limitations,and domain-specific applicability,particularly with regard to the unique challenges involving micro-scale cutting zones in UPM.Special emphasis is placed on micro-scale sensor-integrated tools and self-sensing tools that enable real-time thermal monitoring at cutting edges.Furthermore,we explore thermal monitoring and management techniques for atomic and close-to-atomic scale manufacturing(ACSM),as well as the transformative potential of emerging technologies like artificial intelligence(AI),internet of things(IoT),and data fusion for machining temperature measurement.This review may serve as a reference for UPM cutting temperature measurement research,helping foster the development of optimized process control technologies.
文摘Through systematic cutting experiments, characteristics of the cutting performance of Ti(C, N) based cermets is identified. The experiments were designed to study their resistance,toughness, cutting force, tool-chip friction coefficient and machining quality by comparing them with those of WC based cemented carbides. The cutting data and the regressed empirical formulae would be useful to promote proper application of cermet cutting tool materials.
基金financially supported by the National Natural Science Foundation of China(Nos.92160301,92060203,52175415 and 52205475)the Science Center for Gas Turbine Project(No.P2023-B-IV-003-001)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20210295)the Huaqiao University Engineering Research Center of Brittle Materials Machining(MOE,2023IME-001)。
文摘The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry.
基金Key Development Program of Science and Technology of Heilongjiang Province, China (GB05A501)
文摘At present, most commercial computer-aided manufacturing （CAM） systems are deficient in efficiency and performances on generating tool path during machining impellers. To solve the problem, this article develops a special software to plan cutting path for ruled surface impellers. An approximation algorithm to generate cutting path for machining integral ruled surface impellers is proposed. By fitting sampling data points of an impeller blade into a curve, a model of ruled surface blade of an impeller is built up. Furthermore, by calculating the points where the cutter axis vector intersects the free-form hub surface of an impeller, problems about, for instance, the ambiguity in calculation and machining the wide blade surface with a short flute cutter are solved. Finally, an integral impeller cutting path is planned by way of an integrated cutter location control algorithm. Simulation and machining tests with an impeller are performed on a 5-axis computer numerically controlled （CNC） mill machine, which shows the feasibility of the proposed algorithm.
文摘In machining the particle reinforced aluminum based composite material with high Si content using the cobalt-cemented tungsten carbide micro cutting tools, diamond like carbon （DLC） films are deposited on cobalt-cemented tungsten carbide micro-drills with two-step pretreatment method. Characteristics of DLC coated tools are investigated in bias-enhanced HFCVD system with the optimized hot filament arrangement. The optimization deposition technology is obtained and the wear mechanism of cutting tools is analyzed. The drilling performance of DLC coated tools is verified by the experiments of cutting particle reinforced aluminum based composite material （Si 15% in volume） compared with uncoated ones. Experimental results show that the two-step pretreatment method is appropriate for complex shaped cemented carbide substrates and ensures the good adhesive strength between the diamond film and the substrate. The cutting performance of DLC coated tool is enhanced 10 times when machining the Si particle reinforced aluminum based metal matrix composite compared with that of uncoated ones under the same cutting conditions.
文摘China has a history of more than five thousand years,and its culture is broad and rich.Among many traditional arts,paper-cutting is a special handicraft full of stories and myths.Paper-cutting is a unique art.People use scissors to cut paper into many beautiful shapes,such as flowers,animals,or people.This art only needs simple tools,but it is not as easy as it looks.When we watch the masters cut paper,they can create wonderful patterns in just a few minutes.However,for beginners,a lot of practice and patience are necessary.
文摘A centrifugal pump with a specific speed ns=67 is considered in this study to investigate the impact of blade cutting(at the outlet edge)on the fluid-induced noise,while keeping all the other geometric parameters unchanged.The required unsteady numerical calculations are conducted by applying the RNG k-εturbulence model with the volute dipole being used as the sound source.The results indicate that the internal pressure energy of the centrifugal pump essentially depends on the blade passing frequency and its low-frequency harmonic frequency.Moreover,the pressure pulsation distribution directly affects the noise caused by the centrifugal pump.The sound pressure inside and outside the centrifugal pump and the sound power at the blade passing frequency gradually decrease increasing cutting distance of the impeller blades.When the cutting percentage is 1.21%,that is,the clearance ratio between impeller blade and tongue is 8.57%,the comprehensive performance of the centrifugal pump is the best.
文摘Have we ever seen such a shocking garment in the fashion industry?A down jacket that claims to be one but uses absolutely no down,yet possesses remarkable heating and insulating properties,all designed with a colorless aesthetic.It resembles clothing that has come from the future.The secret behind this captivating design lies in"SOLAMENTR■"developed by Sumitomo Metal Mining Co.,Ltd.
基金supported by the National Natural Science Foundation of China(No.52375443)the Innovative Research Group Project of the National Natural Science Foundation of China(No.51921003)。
文摘To meet the demand for the machining of blisks with narrow cascade channels and twisted blade profiles,especially integral shrouded blisks with shrouds,this paper innovatively proposes a method for dynamic deformation electrochemical cutting of flexible electrodes with arrayed group slit structure.By applying torque to both ends of the flexible electrode,the proposed method produces bending deformation and realizes the processing of a twisted profile.The flexible electrode is an important carrier of this method,and its properties such as elasticity,rigidity,and flow field uniformity have a crucial impact on smooth processing.Therefore,this paper proposes a design theory of flexible electrodes with an arrayed group slit structure and designs flexible electrodes with variable cross-sections.Compared with traditional uniform section tube electrode,the designed flexible electrode was subjected to the corresponding mechanical simulation,flow field simulation,and fluid–structure interaction simulation to investigate the elasticity,rigidity,and flow field uniformity of the flexible electrode.In addition,a deformation device of flexible electrodes was constructed and the corresponding experiments were carried out.Simulations and experiments demonstrate that flexible electrodes with arrayed group slit structures have good comprehensive performance.Finally,typical components were successfully machined to verify the feasibility of the proposed method and the rationality of the designed flexible electrode.It is shown that the proposed method has great potential for the machining of distorted profiles and provides a new idea for the machining of complex profiles.
基金supported by the National Natural Science Foundation of China(Nos.52174099 and 52474168)the Science and Technology Innovation Program of Hunan Province,China(No.2023RC3050)+1 种基金the Natural Science Foundation of Hunan,China(No.2024JJ4064)the Open Fund of the State Key Laboratory of Safety Technology of Metal Mines(No.kfkt2023-01).
文摘Real-time identification of rock strength and cuttability based on monitoring while cutting during excavation is essential for key procedures such as the precise adjustment of excavation parameters and the in-situ modification of hard rocks.This study proposes an in-telligent approach for predicting rock strength and cuttability.A database comprising 132 data sets is established,containing cutting para-meters(such as cutting depth and pick angle),cutting responses(such as specific energy and instantaneous cutting rate),and rock mech-anical parameters collected from conical pick-cutting experiments.These parameters serve as input features for predicting the uniaxial compressive strength and tensile strength of rocks using regression fitting and machine learning methodologies.In addition,rock cuttabil-ity is classified using a combination of the analytic hierarchy process and fuzzy comprehensive evaluation method,and subsequently iden-tified through machine learning approaches.Various models are compared to determine the optimal predictive and classification models.The results indicate that the optimal model for uniaxial compressive strength and tensile strength prediction is the genetic algorithm-optimized backpropagation neural network model,and the optimal model for rock cuttability classification is the radial basis neural network model.
基金supported by the Postdoctoral Fellowship Program of CPSF(No.GZC20233005)the Fundamental Research Funds for the Central Universities(No.2024QN11025)+1 种基金the General Program of National Natural Science Foundation of China(No.52274243)the Hebei Province Natural Science Foundation Ecological Wisdom Mine Joint Fund Project(Nos.D2020402013 and D2022402040)。
文摘The water conductivity of karst collapsed column is affected by multiple factors such as the characteristics of its own column filling,structure and mining disturbance.As a structural water-conducting channel,fault usually plays a controlling role in hydrogeological structure.During the process of mine water hazard prevention and control,it was discovered that the lithology composition,compaction and cementation degree and water physical properties of karst collapsed column fillings were all non-conducting water,but due to the influence of combined development faults,some exploration drill holes showed concentrated water outflow.Based on this,the scientific hypothesis was proposed that fault cutting leads to water conduction in karst collapsed columns.The study comprehensively used methods like chronology,exploration data analysis,and hydrochemical testing to analyze the chronological relationship between faults and karst collapsed columns,their spatial relationship,outlet point distribution and water chemical properties,and the impact of faults on the water-conductivity of karst collapsed columns,which proved the effect of fault cutting on changing water conductivity of karst collapsed column.The research showed that later fault cutting through karst collapsed columns turned the originally non-conductive karst collapsed columns into water-conductive collapsed columns at the fault plane,creating a longitudinally connected water-conducting channel.A new model of fault cutting karst collapsed column to change the original water conductivity of karst collapsed column was proposed.The research results can provide a theoretical basis for the prediction of the water conductivity of the karst collapsed column.According to whether the karst collapsed column was cut by the fault,it was predicted theoretically,so as to determine the key areas of water conductivity detection and prevention and control,and has broad application prospects under the background of source control of mine water disaster.
基金Supported by Jiangsu Provincial Natural Science Foundation(Grant No.BK20231497)Jiangsu Provincial Post Graduate Research&Practice Innovation Program(Grant No.KYCX25_2982)+2 种基金China University of Mining and Technology Graduate Innovation Program(Grant No.2025WLKXJ094)National Natural Science Foundation of China(Grant No.51975573),National Key R&D Program of China(Grant No.2022YFC2905600)Priority Academic Program Development of Jiangsu Higher Education Institute of China.
文摘During the excavation process of deep hard rock tunnels,precutting rock with an abrasive water jet can weaken their strength and improve the efficiency of mining machinery.However,owing to the complex geological environment,abrasive jets cannot fully utilize their rock-cutting performance.To fully exploit the advantages of high-pressure abrasive water jets,five orthogonal experiments were designed for rocks with significant differences in strength.Experimental research has been conducted on the performance of rotating abrasive waterjet-cutting rocks.Moreover,a neural network prediction model for predicting rock-cutting characteristics is established by comprehensively considering rock mechanics parameters and abrasive water jet parameters.The results show that the cutting depth of rocks with different strengths increases nonlinearly with increasing work pressure of the abrasive water jet.The cutting depth decreases exponentially with increasing cutting velocity.The cutting depth first increases and then decreases with increasing target distance,and the best target distance is between 4 mm and 6 mm.The effect of the target distance on the cutting width of rock is the most significant,but the cutting width of high-strength rock is not sensitive to changes in the working parameters of the abrasive water jet.The average relative errors of BP(backpropagation)neural networks optimized by global optimization algorithms in predicting rock cutting depth and width are 13.3%and 5.4%,respectively.This research combines the working characteristics of mining machinery to study the performance of abrasive waterjet rotary cutting of rocks and constructs a predictive model for the performance of abrasive waterjet cutting of rocks that includes rock strength factors.This provides a new solution for quickly adjusting the working parameters of abrasive water jets according to mining conditions.
文摘Shanghai is blazing a new development track powered by dual engines:one is intelligent manufacturing empowered by cutting-edge technologies,and the other is green development driven by low-carbon and energy-saving solutions.On September 10,China Today visited two enterprises in Shanghai-Shanghai Schneider Electric Industrial Control Co.,Ltd.and Huaqin Technology Co.,Ltd.-to observe firsthand how global investment and local innovation are jointly shaping Shanghai’s future of high-quality development.
基金financially supported by the National Natural Science Foundation of China(No.52473228).
文摘The fatigue resistance of casting polyurethane(CPU)is crucial in various sectors,such as construction,healthcare,and the automotive industry.Despite its importance,no studies have reported on the fatigue threshold of CPU.This study employed an advanced Intrinsic Strength Analyzer(ISA)to evaluate the fatigue threshold of CPUs,systematically exploring the effects of three types of isocyanates(PPDI,NDI,TDI)that contribute to hard segment structures based on the cutting method.Employing multiple advanced characterization techniques(XRD,TEM,DSC,AFM),the results indicate that PPDI-based polyurethane exhibits the highest fatigue threshold(182.89 J/m^(2))due to a highest phase separation and a densely packed spherulitic structure,although the hydrogen bonding degree is the lowest(48.3%).Conversely,NDI-based polyurethane,despite having the high hydrogen bonding degree(53.6%),exhibits moderate fatigue performance(122.52 J/m^(2)),likely due to a more scattered microstructure.TDI-based polyurethane,with the highest hydrogen bonding degree(59.1%)but absence of spherulitic structure,shows the lowest fatigue threshold(46.43 J/m^(2)).Compared to common rubbers(NR,NBR,EPDM,BR),the superior fatigue performance of CPU is attributed to its well-organized microstructure,polyurethane possesses a higher fatigue threshold due to its high phase separation degree and orderly and dense spherulitic structure which enhances energy dissipation and reduces crack propagation.
基金the financial support for this research provided by the National Natural Science Foundation of China(Grant Nos.52275470,124115301,and 52105458)the Natural Science Foundation of Beijing(Grant No.3222009).
文摘Vibration cutting has emerged as a promising method for creating surface functional microstructures.However,achieving precise tool setting is a time-consuming process that significantly impacts process efficiency.This study proposes an intelligent approach for tool setting in vibration cutting using machine vision and hearing,divided into two steps.In the first step,machine vision is employed to achieve rough precision in tool setting within tens of micrometers.Subsequently,in the second step,machine hearing utilizes sound pickup to capture vibration audio signals,enabling fine tool adjustment within 1μm precision.The relationship between the spectral intensity of vibration audio and cutting depth is analyzed to establish criteria for tool–workpiece contact.Finally,the efficacy of this approach is validated on an ultra-precision platform,demonstrating that the automated tool-setting process takes no more than 74 s.The total cost of the vision and hearing sensors is less than$1500.
文摘The 3rd China International Supply Chain Expo(hereinafter referred to as the CISCE)is approaching,and NEXWISE Intelligence China Limited(hereinaf ter refer red to as NEXWISE Intelligence),a repeat exhibitor at the event,is ready for the show.In the E4 Hall’s Digital Technology Exhibition Zone,this AI-focused company will showcase its two flagship products and technology systems:“Zhang An Xing”Smart Security and“KuberAI(Producer Platform)”Computing Power Foundation,demonstrating China’s innovative AIdriven efforts in empowering industrial chain security.
基金Supported by National Natural Science Foundation of China(Grant No.52205455)Fujian Provincial Health Technology Project(Grant Nos.2022CXA005,2022CXA015)。
文摘Cardiovascular disease is the leading cause of human mortality,and calcified tissue blocking blood vessels is the main cause of major adverse cardiovascular events(MACE).Rotational Atherectomy(RA)is a minimally invasive catheterbased treatment method that involves high-speed cutting of calcified tissue using miniature tools for removal.However,the cutting forces,heat,and debris can induce tissue damage and give rise to serious surgical complications.To enhance the effectiveness and efficiency of RA,a novel eccentric rotational cutting tool,with one side comprising axial and circumferential staggered micro-blades,was designed and fabricated in this study.In addition,a series of experiments were conducted to analyze their performance across five dimensions:tool kinematics,force,temperature,debris,and surface morphology of the specimens.Experimental results show that the force,temperature and debris size of the novel tool were well inhibited at the highest rotational speed.For the tool of standard clinical size(diameter 1.25 mm),the maximum force is 0.75 N,with a maximum temperature rise in the operation area of 1.09℃.Debris distribution followed a normal distribution pattern,with 90%of debris measuring smaller than 9.12μm.All tool metrics met clinical safety requirements,indicating its superior performance.This study provides a new idea for the design of calcified tissue removal tools,and contributes positively to the advancement of RA.
基金Supported by National Natural Science Foundation of China(Grant No.52175528).
文摘High-speed milling(HSM)is advantageous for machining high-quality complex-structure surface components with various materials.Identifying and estimating cutting force signals for characterizing HSM is of high significance.However,considering the tool runout and size effects,many proposed models focus on the material and mechanical characteristics.This study presents a novel approach for predicting micromilling cutting forces using a semianalytical multidimensional model that integrates experimental empirical data and a mechanical theoretical force model.A novel analytical optimization approach is provided to identify the cutting forces,classify the cutting states,and determine the tool runout using an adaptive algorithm that simplifies modeling and calculation.The instantaneous un-deformed chip thickness(IUCT)is determined from the trochoidal trajectories of each tool flute and optimized using the bisection method.Herein,the computational efficiency is improved,and the errors are clarified.The tool runout parameters are identified from the processed displacement signals and determined from the preprocessed vibration signals using an adaptive signal processing method.It is reliable and stable for determining tool runout and is an effective foundation for the force model.This approach is verified using HSM tests.Herein,the determination coefficients are stable above 0.9.It is convenient and efficient for achieving the key intermediate parameters(IUCT and tool runout),which can be generalized to various machining conditions and operations.
基金funded by the key research on industrialization technologies of low-cost highenergy-density cathode materials(project number:2023GY008)the Sichuan Provincial Science and Technology Program(project number:2024NSFSC1406).
文摘To address the issue of uneven temperature distribution in shale gas oil-based drill cuttings pyrolysis furnaces,a numerical model was developed using Fluent software.The effects of nitrogen flow rate,heating tube spacing,and furnace dimensions on the internal temperature field were thoroughly analyzed from a mechanistic perspective.The results indicated that non-uniform radiation from the heating tubes and flow disturbances induced by the nitrogen stream were the primary causes of localized heat concentration.Under no-load conditions,the maximum deviation between simulated and on-site measured temperatures was 1.5%,validating the model’s accuracy.Further-more,this study investigated the trade-offs between temperature uniformity,energy consumption,and construction costs.The findings provide a crucial design basis and a reliable simulation platform for developing and optimizing pyrolysis equipment.
