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Effect of die coating on surface crack depth of hot extruded 7075 aluminum alloy

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Friction 2023年第7期11卷 1212-1224页

作者： Tatsuya FUNAZUKA Kuniaki DOHDA Norio TAKATSUJI chengliang hu Ngernbamrung SUKUNTHAKAN Faculty of Engineering University of ToyamaToyama 9308555Japan Department of Mechanical Engineering Northwestern UniversityEvanston 60201USA Institute of Forming Technology&Equipment School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200030China Metal and Manufacturing Process Research Group National Metal and Materials Technology CenterPathumthani 12120Thailand

The aluminum alloys belonging to the 7000 series are high-strength alloys used in a wide variety of products for weight *** are primarily used in the field of transportation and *** these,the A7075 alloy has the highest strength and is expected to be applicable in a wide range of fields,such as aircraft components and sports ***,it has high deformation resistance and is prone to surface defects,which is called *** typically occurs at high temperatures and high ram speeds,and adversely affects *** localized melting of Zn and additive compounds,due to the heat generated during the process,is considered to cause *** this study,the effect of friction,heat,and tearing at the tool-metal interface was mitigated by improving the die surface *** reduced friction eliminated recrystallization by preventing the temperature from increasing to recrystallization *** addition,an AlCrN coating was adopted instead of nitriding to improve the die surface *** tearing size and heat generated when using the AlCrN coating were found to be ***,the grain size observed in the tearing region on the extruded surface was *** simulations using the shear friction coefficient m observed from friction tests indicate that the use of the AlCrN coating improved the material ***,the AlCrN coating is considered effective for reducing friction at the interface and preventing the recrystallization of the extruded *** the aforementioned results,it can be inferred that a die coating can reduce the tearing sensitivity and increase the productivity of the A7075 alloy.

关键词： hot extrusion 7075 aluminum alloy die coating tearing

Evaluation of dry-in-place lubricants for cold forging by using an optimal steady combined forward and backward extrusion testing method

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Friction 2023年第10期11卷 1862-1876页

作者： chengliang hu Shogo OSAKI Baixuan CAI Mitsuru AOYAMA Kuniaki DOHDA Institute of Forming Technology&Equipment School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200030China Central Research Laboratories Nihon Parkerizing Co.Ltd.Hiratsuka-shi 254-0012Japan Department of Mechanical Engineering Northwestern UniversityEvanston 60208-3111USA

This study evaluated dry-in-place lubricants used for cold forging.A group of isothermal compression tests with a strain rate(ε)e&range of 0.001–1 s^(−1) and temperature(T)range of 30–400℃ were *** flow stress(σ)curves of annealed steel S45C were obtained,and a corresponding Hensel–Spittel model was developed to support finite element(FE)*** sensitivity of the steady combined forward and backward extrusion(SCFBE)test proposed in another study was improved by approximately 20%after it was optimized using the results of the FE *** parameters were identified,and the calibration curves after optimization were *** the basis of the optimized test,a friction testing setup with a heating system was developed,in which the die temperature could be adjusted from room temperature(RT)to 230℃.Three dry-in-place lubricants and conventional phosphating lubricant were tested,and the friction factors(m),forming loads,and ejection loads were *** surface features of the specimens after testing were also *** to the testing results,of the three tested dry-in-place lubricants,the mica type was the *** addition,the optimized friction testing design was verified as effective.

关键词： lubrication optimization sensitivity friction factor(m) forming load cold forging

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热成形条件下软磁材料的磁感应强度预测模型

机械工程学报 2024年第2期60卷 132-139,149页

作者：胡成亮苗宏量曾凡赵震汤敏俊汤晓峰上海交通大学模具CAD国家工程研究中心上海200030 上海交通大学塑性成形技术与装备研究院上海200030 江苏龙城精锻有限公司常州213100

爪极是车用爪极式发电机中的重要零件之一,其磁性能直接影响对应发电机的发电效率。热锻是当前工业界爪极制造的常用工艺,面向爪极热锻成形本文开展了爪极锻件磁性能的预测研究工作。以爪极用低碳钢软磁材料为对象,构建热成形条件下的... 详细信息

爪极是车用爪极式发电机中的重要零件之一,其磁性能直接影响对应发电机的发电效率。热锻是当前工业界爪极制造的常用工艺,面向爪极热锻成形本文开展了爪极锻件磁性能的预测研究工作。以爪极用低碳钢软磁材料为对象,构建热成形条件下的磁感应强度预测模型,并介绍了该模型的主要参数及其确定方法;对爪极热锻过程开展数值模拟,引入磁感应强度预测模型试着对爪极锻件磁感应强度分布的进行预测;同时,在爪极预锻不同变形阶段的中心部位及终锻件不同位置进行取样,采用磁环法对具体磁感应强度进行实测,与模拟计算结果进行对比分析;模拟预测与实际测量值间最大误差小于10%,说明该预测模型具有良好的适用性,可为后续面向磁性能提升的爪极工艺设计优化奠定基础。

关键词：爪极磁感应强度热成形预测模型数值模拟

A novel phenomenological model using a sine function for finite-element simulation of large-strain hot deformation

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Science China(Technological Sciences) 2018年第5期61卷 748-760页

作者： ZENG Fan hu chengliang ZHAO Zhen Institute of Forming Technology & Equipment Shanghai Jiao Tong University

In hot deformation, the flow stress curves of steels always present as two typical types: at relatively high temperature and low strain rate, the flow stress may first increase and then attain a steady value without reaching an obvious peak stress; in other situations, the flow stress decreases after reaching peak stress and then attains a steady value. A new phenomenological model,described by a sine-function equation, is proposed to define the relationship between flow stress and deformation parameters. A series of isothermal compressions for a carbon steel were carried out, as a case study, to obtain basic experimental *** of the new model were sequentially determined. The predicted results of the proposed model were compared with actual measured data. Good accuracy was found in the standard statistical parameters of correlation coefficient, root mean square error, and average absolute relative error with the values of 0.935, 7.137 MPa and 4.352%, respectively. Discussion of applications of different models in finite-element simulation demonstrated the benefit of the new model. When comparing the simulation results of three different deformation patterns with large strain, the new model showed 10%–20% lower predicted forming load than the original Arrhenius equation, and better applicability and reliability than modified Arrhenius equations.

关键词：模型显示有限元素现象学模拟 Arrhenius 正弦流动压力测量数据

Single-shot phase retrieval for randomly fluctuated and obstructed vortex beams

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 72-80页

作者： Hao Zhang Jun’an Zhu Xingyuan Lu Zhiquan hu Jianbo Gao Kun Liu Qiwen Zhan Yangjian Cai chengliang Zhao School of Physical Science and Technology Soochow UniversitySuzhou 215006China School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shandong Provincial Engineering and Technical Center of Light Manipulations Shandong Provincial Key Laboratory of Optics and Photonic DeviceSchool of Physics and ElectronicsShandong Normal UniversityJinan 250358China Joint Research Center of Light Manipulation Science and Photonic Integrated Chip of East China Normal University and Shandong Normal University East China Normal UniversityShanghai 200241China

Vortex beams with orbital angular momentum play a crucial role in increasing the information capacity in optical *** magnitude of orbital angular momentum determines the ability of information *** practice,a vortex beam can encounter random objects or turbulence during free-space propagation,resulting in information ***,accurately measuring the orbital angular momentum of a randomly fluctuated and obstructed vortex beam is a considerable ***,we propose a single-shot method for the phase retrieval of a randomly fluctuated and obstructed vortex beam by combining the phase-shift theorem and self-reference *** results reveal that the sign and magnitude of the initial orbital angular momentum can be simultaneously determined based on their quantitative relation with the number of coherence singularities on the observation plane,thus addressing the effects of random occlusion and atmospheric *** proposed method considerably improved the accurate decoding of orbital angular momentum information in nonideal freespace optical communications.

关键词： optical vortex phase retrieve orbital angular momentum measurement antiturbulence antidisturbance

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Non-destructive Measurement of Magnetic Properties of Claw Pole

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Chinese Journal of Mechanical Engineering 2019年第5期32卷 23-33页

作者： chengliang hu Xuejiao Bai Minjun Tang Xiaofeng Tang Zhen Zhao Institute of Forming Technology&Equipment School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200030China Jiangsu Longcheng Precision Forging Co. Ltd.Jiangsu 213100China

The magnetic properties of the claw pole have a direct effect on the output power of a generator Many methods can be used to measure these magnetic properties,each with its own advantages,but an important shortcoming is that all are *** this study,a new non-destructive method to measure the magnetic properties of claw pole was proposed and a corresponding testing set-up was designed.A finite-element model was constructed to simulate the measurement *** proved that the measured magnetization-like curves had good agreement with the trend of the input magnetic curves and the effect of the positioning error in the measuring process could be *** further validate the new method,seven types of claw poles of different materials subjected to different heat-treatment processes were forged and tested by both the new method and the conventional ring-sample *** with the latter,the new method showed better consistency,relatively higher accuracy,and much stronger stability of measurement results;however,its sensitivity needs to be *** effects of material compositions and heat-treatment parameters on the magnetic properties of the claw pole were briefly analyzed.

关键词： Claw pole Magnetic property Measurement Ring sample Accuracy Stability

The solute carrier transporters and the brain:Physiological and pharmacological implications

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Asian Journal of Pharmaceutical Sciences 2020年第2期15卷 131-144页

作者： chengliang hu Lei Tao Xizhi Cao Ligong Chen School of Pharmaceutical Sciences Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology(Ministry of Education)Tsinghua UniversityBeijing 100084China Advanced Innovation Center for human Brain Protection Beijing Anding HospitalCapital Medical UniversityBeijing 100088China Collaborative Innovation Center for Biotherapy State Key Laboratory of Biotherapy and Cancer CenterWest China HospitalWest China Medical SchoolSichuan UniversityChengdu 610041China

Solute carriers(SLCs)are the largest family of transmembrane transporters that determine the exchange of various substances,including nutrients,ions,metabolites,and drugs across biological *** date,the presence of about 287 SLC genes have been identified in the brain,among which mutations or the resultant dysfunctions of 71 SLC genes have been reported to be correlated with human brain *** increasing interest in SLCs have focused on drug development,SLCs are currently still under-explored as drug targets,especially in the *** summarize the main substrates and functions of SLCs that are expressed in the brain,with an emphasis on selected SLCs that are important physiologically,pathologically,and pharmacologically in the blood-brain barrier,astrocytes,and *** suggests that a fraction of SLCs are regulated along with the occurrences of brain disorders,among which epilepsy,neurodegenerative diseases,and autism are *** the review of SLCs involved in the onset and procession of brain disorders,we hope these SLCs will be screened as promising drug targets to improve drug delivery to the brain.

关键词： Solute carrier transporter Brain disorder Blood-brain barrier Drug

Galling phenomena in metal forming

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Friction 2021年第4期9卷 665-685页

作者： Kuniaki DOHDA Masahito YAMAMOTO chengliang hu Laurent DUBAR Kornel F.EHMANN Department of Mechanical Engineering Northwestern UniversityEvanstonIL 60208-3111USA Manufacturing Engineering Center NSKLtd.Fujisawa-Shi 251-8501Japan Institute of Forming Technology and Equipment School of Materials and EngineeringShanghai Jiao Tong UniversityShanghai 200240China LAMIH UMR CNRS 8201 Universite Polytechnique Hauts-de-FranceValenciennes Cedex 959313France

Galling phenomena in metal forming not only affect the quality of the engineered surfaces but also the success or failure of the manufacturing operation *** paper reviews the different galling conditions in sheet and bulk metal forming processes along with their evolution and the effects of temperature on galling.A group of anti-galling methods employed to prevent galling defects are also presented in *** techniques for quantitatively measuring galling are introduced,and the related prediction models,including friction,wear,and galling growth models,are presented to better understand the underlying *** phenomena in other processes similar to those occurring in metal forming are also examined to suggest different ways of further studying galling in metal ***,future research directions for the study of galling in metal forming are suggested.

关键词： galling metal forming friction wear adhesion anti-galling

Analytical Solution of Thermo-Elastic-Plastic Deformation of the Combined Forging Die

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Journal of Shanghai Jiaotong university(Science) 2023年第2期28卷 280-288页

作者：曹民业苗宏量胡成亮赵震 Institute of Forming Technology&Equipment School of Materials Science and EngineeringNational Engineering Research Center of Die and Mold CADShanghai Jiao Tong UniversityShanghai 200030China

On the multi-layer forging die used in daily life,stressed ring can strength the die structure within elastic deformation and the die material can be self-strengthened through uniform plastic deformation by autofrettage effect,whereas the thermal effect generated during forging process can directly influence the stress state and dimension of the forging die in *** this study,an analytical solution of the thermo-elastic-plastic deformation in the forging die is *** relationships between the radial and circumferential stresses and the temperature distribution,which are directly related to geometric parameters,material properties and working pressure,are *** helps to better understand the thermo-elastic-plastic deformation behavior of the die and design the combined forging die to achieve long service life and high accuracy product.

关键词： thermal deformation elastic deformation plastic deformation die temperature