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Research Square 2021年

作者： Xu, Yundou Yang, Fan Mei, Youen Zhang, Dongsheng Zhou, Yulin Zhao, Yongsheng Laboratory of Parallel Robot and Mechatronic System of Hebei Province Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology Science of Ministry of National Education Yanshan University Qinhuangdao006004 China School of Mechanical Engineering Yanshan University Qinhuangdao066004 China Tencent Robotics X Tencent Holdings Shenzhen518057 China

In the present study, the over-constrained hybrid manipulator R(2RPR)R/SP+RR is considered as the research objective. In this paper, kinematics of the hybrid manipulator, including the forward and inverse position, are analyzed. Then, the workspace is checked based on the inverse position solution to evaluate whether the workspace of the hybrid manipulator meets the requirements, and the actual workspace of the hybrid robot is analyzed. After that, the force analysis of the over-constrained parallel mechanism is carried out, and an ADAMS-ANSYS rigid-flexible hybrid body model is established to verify the simulation. Based on the obtained results from the force analysis, the manipulator structure is design. Then, the structure optimization is carried out to improve the robot stiffness. Finally, calibration and workspace verification experiments are performed on the prototype, cutting experiment of an S-shaped aluminum alloy workpiece is completed, and the experiment verifies the processing ability of the prototype and proves that the prototype has good application prospects. © 2021, CC BY.

关键词： Kinematics

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Research on double differential pressure dynamic flowmeter

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High technology Letters 2019年第4期25卷 378-385页

作者： Liu Tao Zuo Zhibing Yin Zhigang Hebei Province Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityQinhuangdao 066004P.R.China Key Laboratory of Education Ministry for Advanced Forging Press Technology and Science Yanshan UniversityQinhuangdao 066004P.R.China

When testing an electrohydraulic proportional valve,it is necessary to test the high frequency dynamic flow with *** of the limitation of the piston stroke,a no-load hydraulic cylinder is only suitable for a reciprocating symmetrical dynamic flow *** the traditional differential pressure flowmeter is affected by viscosity and inertia of the fluid,it is only suitable for measuring steady ***,a new type of double pressure differential dynamic flowmeter is designed to improve the traditional differential pressure *** influence of fluid viscosity and inertia in the flow process are negated by subtracting the differential pressure in section expansion from the differential pressure in section *** double differential pressure flowmeter is modeled and a flow meter prototype is ***,the flow coefficients are identified and corrected by a practical ***,the dynamic performance and steady-state precision of the flowmeter are verified by comparing with the test results of the no-load hydraulic *** double differential pressure dynamic flowmeter is proven to measure dynamic flow accurately,especially at higher dynamic frequencies.

关键词： dynamic flowmeter double differential pressure contrast experiment coefficient correction

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Kinematic Characteristics and Dynamics Analysis of the Tetrahedral Deployable Mechanism Based on the Screw Theory

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Jiqiren/Robot 2020年第1期42卷 21-28and38页

作者： Han, Bo Han, Yuanyuan Xu, Yundou Zheng, Dong Yao, Jiantao Zhao, Yongsheng Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Qinhuangdao066004 China Department of Mathematics and Computer Science Hengshui University Hengshui053000 China

In order to solve the modeling and analysis problems of the kinematics and dynamics of the spaceborne tetrahedral space deployable antenna, a kinematics and dynamics characteristics analysis method based on screw theory is established. Firstly, configuration and geometric characteristics of the 3RR-3RRR tetrahedral deployable mechanism are analyzed, its screw constrained topology diagram is obtained based on screw theory, and its degree of freedom (DOF) is calculated to be only one. Then, the kinematics analysis of the mechanism is conducted, the velocities of the components are obtained through the combinatorial operation of kinematic twists, and the Jacobian matrix of this mechanism is also obtained. The 6-dimensional acceleration of each component is expressed by the screw derivative, and the angular accelerations and centroid linear accelerations of the node disks and rods are deduced. Finally, the dynamic equation is established based on the Newton-Euler equation and the principle of virtual work, and the numerical calculation and simulation verification are carried out. The simulation results are completely consistent with the numerical results, which verifies the correctness of the kinematics and dynamics characteristics analysis method based on screw theory. Every parameter has clear physical meanings in the analysis based on the proposed method, and the analysis process is easy to program due to its stylization and is suitable for the analysis of such spatial deployable mechanisms. © 2020, Science Press. All right reserved.

关键词： Screws

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Additive manufacturing of magnesium and its alloys: process-formabilitymicrostructure-performance relationship and underlying mechanism

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International Journal of Extreme Manufacturing 2023年第4期5卷 247-290页

作者： Shang Sui Shuai Guo Dong Ma Can Guo Xiangquan Wu Zhongming Zhang Chunjie Xu Dan Shechtman Sergei Remennik Daniel Safranchik Rimma Lapovok School of Materials Science and Engineering Xi’an University of TechnologyXi’anShaanxi 710048People’s Republic of China Xi’an Shechtman Nobel Prize New Materials Institute Xi’an 710048People’s Republic of China Xi’an Key Laboratory of Advanced Magnesium Alloy Additive Manufacturing and Precision Forming Xi’anShaanxi 710048People’s Republic of China School of Materials Science and Engineering Liaocheng UniversityLiaochengShandong 252059People’s Republic of China Department of Materials Science and Engineering Technion-Israel Institute of TechnologyHaifa 32000Israel Center for Nanoscience&Nanotechnology Hebrew University of JerusalemEdmond J.Safra CampusJerusalem 91904Israel Israel Institute of Metals Technion CityHaifa 3200003Israel Institute for Machine Elements Engineering Design and ManufacturingFreiberg 09599Germany Geelong Waurn Ponds Campus Deakin UniversityPigdons RoadGeelongVic 3216Australia

Magnesium and its alloys,as a promising class of materials,is popular in lightweight application and biomedical implants due to their low density and good *** manufacturing(AM)of Mg and its alloys is of growing interest in academia and *** domain-by-domain localized forming characteristics of AM leads to unique microstructures and performances of AM-process Mg and its alloys,which are different from those of traditionally manufactured ***,the intrinsic mechanisms still remain unclear and need to be in-depth ***,this work aims to discuss and analyze the possible underlying mechanisms regarding defect appearance and elimination,microstructure formation and evolution,and performance improvement,based on presenting a comprehensive and systematic review on the relationship between process parameters,forming quality,microstructure characteristics and resultant ***,some key perspectives requiring focus for further progression are highlighted to promote development of AM-processed Mg and its alloys and accelerate their industrialization.

关键词： additive manufacturing magnesium alloys underlying mechanisms forming quality microstructure characteristics and properties

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Comprehensive insights into electrical properties enhancement of boron‑sulfur co-doped diamond via ion implantation: First principles calculation and experimental validation

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Diamond and Related Materials 2025年 157卷

作者： Wang Zhao Bing Wang Zhanqiang Liu Honglu Li Zhaoliang Yu Pengyang Wang School of Mechanical Engineering Shandong University Jinan 250061 PR China Shandong Key Laboratory of High Performance Tools and System Jinan 250061 PR China Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education Jinan 250061 PR China State Key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Jinan 250061 PR China Department of Computer and Information Science University of Macau PR China

Diamond presents great potential for applications as high‑temperature and high-power electronic devices as a new generation of semiconductor material. However, the inherent low electrical conductivity limits diamond applications. This study aims to reveal the conductive mechanism of boron (B)‑sulfur (S) co-doped diamond for conductivity enhancement with density-functional theory (DFT) calculations and ion implantation experiments. Firstly, the effects of B-S co-doping on diamond's electrical properties are investigated by analyzing the band structure and electron transport at different doping ratios using DFT. Secondly, Precision doping into single-crystal diamond is achieved via ion implantation, followed by annealing to remove lattice defects. Thirdly, the lattice integrity after doping is assessed by Raman spectroscopy, the chemical compositions and bonding states are analyzed by X-ray photoelectron spectroscopy, and the electrical properties of the co-doped diamonds are evaluated by Hall effect measurements. First-principles calculations show that B-S co-doping also generates additional acceptor and donor energy levels that couple, leading to more uniformly distributed impurity levels, a narrower band gap, altered electron transitions, and coupling in specific orbitals. These modifications imply that a B:S co-doping ratio of 1:2 may be favorable for enhanced carrier activation and improved electrical transport behavior. Based on first-principles calculations and Hall effect experiments the optimal conductivity occurs at a B:S ratio of 1:2, which gives better conductivity compared to single doping or other ratios. These findings Preliminary provide complementary theoretical and experimental evidence supporting the modulation of electrical conductivity through B-S co-doping.

关键词： Boron and sulfur co-doping Diamond semiconductor Electrical property First principles calculation Ion implantation

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Microstructures and mechanical properties of Ti3Al/Ni-based superalloy joints brazed with AuNi filler metal

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Journal of Materials Science & technology 2019年第9期35卷 2070-2078页

作者： H.S. Ren H.P.Xiong W.M. Long B. Chen Y.X. Shen J. Pang Welding and Plastic Forming Division Beijing Institutes of Aeronautical MatericalBeijing 100095China State Key Laboratory of Advanced Brazing Filler Metals and Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001 China Department of Material Science and Engineering Beihang UniversityBeijing 100191China

For the purpose of high-temperature service and the weight reduction in aviation engineering applications, the dissimilar joining of Ti3Al-based alloy to Ni-based superalloy (GH536) was conducted using Au-17.5Ni (wt%) brazing filler metal. The microstructure and chemical composition at the interfaces were investigated by scanning electron microscope, X-ray diffraction and transmission electron microscope. The diffusion behaviors of elements were analyzed as well. The results indicated that the Ti3Al/GH536 joint microstructure was characterized by multiple layer structures. Element Ni from Au-Ni filler metal reacted with Ti3Al base metal, leading to the formation of AlNi2Ti and NiTi compounds. Element Ni from Ti3Al base metal reacted with Ni and thus Ni3Nb phase was detected in the joint central area. Due to the dissolution of Ni-based superalloy,(Ni,Au) solid solution ((Ni,Au)ss) and Ni-rich phase were visible adjacent to the superalloy side. The average tensile strength of all the joints brazed at 1253 K for 5-20 min was above 356 MPa at room-temperature. In particular, the joints brazed at 1253 K/15 min presented the maximum tensile strength of434 MPa at room-temperature, and the strength of 314 MPa was maintained at 923 K. AlNi2Ti compound resulted in the highest hardness area and the fracture of the samples subjected to the tensile test mainly occurred in this zone.

关键词： Ti3Al-based alloy Ni-based superalloy Brazing Microstructure Tensile strength

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Ysz: EU, Er as a Potential Dual-Sensor for Simultaneous Pressure and Temperature Measurements in High-Temperature Environment

SSRN

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SSRN 2022年

作者： Yang, Lixia Fu, Yating Liu, Yingzheng Peng, Di Chen, Zhaofeng Zhao, Xiaofeng Kou, Zongde International Laboratory for Insulation and Energy Efficiency Materials College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics 29 Yudao St. Nanjing210016 China Key Lab of Education Ministry for Power Machinery and Engineering School of Mechanical Engineering Shanghai Jiao Tong University 800 Dongchuan Road Shanghai200240 China Shanghai Key Laboratory of Advanced High-Temperature Materials and Precision Forming School of Material Science and Engineering Shanghai Jiao Tong University 800 Dongchuan Road Shanghai200240 China School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing210094 China

In this study, the phosphorescence properties of Eu 3+ and Er 3+ co-doped yttria stabilized zirconia (YSZ: Eu 3+ , Er 3+ ) as a function of temperature and oxygen partial pressure are investigated to explore the possibility of using this phosphor for pressure and temperature measurements at high temperature (up to 600°C). The YSZ: Eu 3+ , Er 3+ phosphors have a fixed Eu 3+ concentration and a varied Er 3+ concentration (0.5 ~ 5 mol%). The phosphorescence intensity and lifetime of Eu 3+ bands are sensitive to both temperature and oxygen partial pressure when temperature exceeds 400 °C. This oxygen/pressure sensitivity is related to the oxygen vacancy-induced non-radiative decay through charge transfer state (CTS), and is inversely correlated with Er 3+ concentration. In contrast, the phosphorescence intensity and lifetime of Er 3+ bands are temperature-sensitive but oxygen-insensitive, which is related to the dominant oxygen-independent 4 S 3/2 → 2 H 11/2 transition. Accordingly, two measurement strategies are proposed including an intensity ratio method and a lifetime method. The intensity ratio of the oxygen-sensitive Eu 3+ bands and the oxygen-insensitive Er 3+ reference bands is capable of 2D pressure measurement using a dual-camera system. But temperature-induced errors exist due to the temperature-sensitivity of intensity ratio. Simultaneous pressure and temperature measurements (point by point) can be achieved utilizing two PMTs that record the lifetimes of Eu 3+ and Er 3+ , respectively. This method can resolve the issue of temperature sensitivity of Eu 3+ and accurately correct the temperature-induced errors. The YSZ:Eu, Er phosphors show great potential for applications in high-temperature environment where the existing organic PSPs and TSPs cannot survive. © 2022, The Authors. All rights reserved.

关键词： Yttria stabilized zirconia

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Correction: Response Mechanism of Mechanical Behavior with Mg Plate Microstructure Evolution During Al/Mg/Al Composite Plate Rolled by Hard Plate

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Metals and Materials International 2023年第7期29卷 2017-2017页

作者： Gao, Rong He Li, Feng Niu, Wen Tao Huo, Peng Da School of Materials Science and Chemical Engineering Harbin University of Science and Technology Harbin People’s Republic of China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of Education Harbin University of Science and Technology Harbin People’s Republic of China Heilongjiang Provincial Key Laboratory of Light Metal Materials Modification & Green Forming Technology Harbin People’s Republic of China

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Experimental characterization and formation mechanism of micro/nano-scale DRX grains in FGH96 machined surface layer

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Materials Today Communications 2025年

作者： Xuepeng Wang Xiaoping Ren Zhanqiang Liu Yinghao Li Bing Wang Jinfu Zhao Yukui Cai School of Mechanical Engineering Shandong University Jinan 250061 PR China Shandong Key Laboratory of High Performance Tools and System Jinan 250061 PR China Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education Jinan 250061 PR China State Key Laboratory of Advanced Equipment and Technology for Metal Forming Shandong University Jinan 250061 PR China School of Mechanical Electrical & Information Engineering Shandong University Weihai 264209 PR China

The microstructure of the machined surface layer after cutting process determines the service performance of the workpiece. Based on the multi-scale characterization of the microstructure of machined surface layer, combined with the thermo-mechanical loadings, the mixed dynamic recrystallization mechanism of micron/nano-scale grain refinement of FGH96 machined surface layer is given. This mechanism points out that the continuous dynamic recrystallization mechanism characterized by sub-grain rotation is the main reason for grain refinement on the machined surface during the instantaneous high temperature and high strain rate deformation of FGH96, accompanied by the existence of discontinuous dynamic recrystallization mechanism. It is worth noting that the EDS element analysis shows that the γ' precipitates of the machined surface layer is partially dissolved and grain nucleation was found at the grain boundary near the γ' precipitates. This means that the γ' precipitates play an important role in the dynamic recrystallization process. This study provides a theoretical basis for understanding the cutting mechanism of powder superalloys and contributes to the further improvement of high-quality and high-efficiency cutting technology.

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On the strain and strain-rate hardenability of additively manufactured austenitic stainless steels

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Materials Science and Engineering: A 2025年 939卷

作者： Kong, Decheng Xu, Xuexu Ni, Xiaoqing Zhu, Guoliang Dong, Chaofang Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai200240 China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing100083 China Research and Application Center of Additive Manufacturing Materials Shanghai Research Institute of Materials Co. Ltd. Shanghai200437 China

Dislocation cells (DCs) are peculiar substructures frequently observed in plastically deformed (PD) and additively manufactured (AM) metals and alloys, and the latter typically exhibit visible elemental segregation along the DC boundaries. This work comparatively analyzes the DC effects on the strain-hardening and strain-rate hardening capabilities of PD and AM austenitic stainless steels (ASSs). The findings suggest that the presence of Cr/Mo-decorated DCs contributes to superior yield strength and admirable mechanical stability for AM ASSs. However, the high critical stress required for deformation twinning leads to a decreased twinning ability, resulting in lower strain hardening capability for AM ASSs compared to PD counterparts. Additionally, micron-sized DCs significantly enhance the strain-rate hardening capability of the AM parts by reducing the dislocation-free path. The inherent DC substructure of these AM materials demonstrates promising energy-absorption performance under extreme-speed deformation conditions, particularly combined with intricate structural design advantages. © 2025 Elsevier B.V.

关键词： Austenitic stainless steel

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