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Assessing the corrosion protection property of coatings loaded with corrosion inhibitors using the real-time atmospheric corrosion monitoring technique

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 119-126页

作者： Xiaoxue Wang Lulu Jin Jinke Wang Rongqiao Wang Xiuchun Liu Kai Gao Jingli Sun Yong Yuan Lingwei Ma Hongchang Qian dawei zhang School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beijing Institute of Space Long March Vehicle Beijing 100076China National Materials Corrosion and Protection Data Center University of Science and Technology BeijingBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China Shanghai Spaceflight Precision Machinery Institute Shanghai 201600China

The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal ***,limited studies have applied ACM to the corrosion protection properties of organic *** study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over *** with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in *** the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy *** trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface *** alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic *** with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.

关键词： atmospheric corrosion monitoring technology corrosion inhibitor coating carbon steel corrosion protection

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Frictional behavior during cold ring compression process of aluminum alloy 5052

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Chinese Journal of Aeronautics 2021年第5期34卷 47-64页

作者： dawei zhang Guangcan YANG Shengdun ZHAO School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710049China

The friction is the considerable boundary condition in bulk metal *** this paper,the ring compression test was used to evaluate the friction coefficient and factor in Coulomb friction model and Tresca friction model for the plastic deformation of aluminum alloy *** micro-macro analysis method combining surface morphology and micro-texture was used to explore the friction behaviors in AA5052 cold forming *** general,the magnitude(μor m)of friction changes before and after a deformation threshold during ring *** maximum change rate of the magnitude(μor m)before and after the deformation threshold is close to 18.5%under the present experimental conditions,and the change rate decreases with increasing loading *** lubrication using MoS_(2) is better than that using oil at lower speeds(0.15 mm/s,1.5 mm/s),but the lubrications for MoS_(2) and oil are similar at higher speeds(15 mm/s).The surface roughness,three-dimensional topography,and surface texture of compressed ring have a sudden change around the deformation threshold,which deviate from the previous evolution *** increased friction after deformation threshold also promotes the formation of sufficient shear strain layer in the subsurface plane of the compressed ring,and then it hinders the formation of the typical deformation textures withβ-oriented line and promotes the appearance of shear textures such as{001}(110),{111}(uvw)and{hkl}{110)textures.

关键词： Deformation threshold Magnitude of friction Ring compression test Shear texture Surface feature

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Universal machine learning potential accelerates atomistic modeling of materials

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Journal of Energy Chemistry 2023年第8期83卷 1-2,I0002页

作者： Zhongheng Fu dawei zhang Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology Beijing.Beijing 100083China National Materials Corrosion and Protection Data Center University of Science and Technology BeijingBeijing 100083China

With the rapid development of computer techniques,atomistic modeling is playing an increasingly important role in understanding the structure-activity relationship of *** dynamics (MD) is a computational simulation approach to predicting the structural evolution of an atomic system over time,widely used to understand physical and chemical phenomena including phase transition,diffusion,crystallization,and reaction [1].

关键词： Machinelearning Atomisticmodeling Neural networkpotential Solid-statematerials

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Design and Dynamic Modeling of a 2-DOF Decoupled Flexure-Based Mechanism

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Chinese Journal of Mechanical Engineering 2012年第4期25卷 688-696页

作者： QIN Yanding TIAN Yanling zhang dawei School of Mechanical Engineering Tianjin University Tianjin 300072 China

Flexure mechanisms with decoupled characteristics have been widely utilized in precision positioning ***,these mechanisms suffer from either slow response or low load ***,asymmetric design always leads to thermal *** order to solve these issues,a novel 2-DOF decoupled mechanism is developed by monolithically manufacturing sets of statically indeterminate symmetric（SIS） flexure structures in *** design helps to eliminate the thermal error and Finite Element Analysis（FEA） results show that the maximum coupling ratio between X and Y axes is below 0.25% when a maximum pretension force of 200 N is *** ignoring the mass effect,all the SIS flexure structures are simplified to ＂spring-damper＂ components,from which the static and dynamics model are *** relation between the first resonant frequency of the mechanism and the load is investigated by incorporating the load mass into the proposed dynamics *** results show that even with a load of 0.5 kg,the first resonant frequency is still higher than 300 Hz,indicating a high load *** mechanism＇s static and dynamic performances are experimentally *** linear stiffnesses of the mechanism at the working platform and at the driving point are measured to be 3.563 0 N·μm-1 and 3.362 1 N·μm-1,*** corresponding estimation values from analytical models are 3.405 7 N·μm-1 and 3.381 7 N·μm-1,which correspond to estimation errors of-4.41% and 0.6%,*** an additional load of 0.16 kg,the measured and estimated first resonant frequencies are 362 Hz and 365 Hz,*** estimation error is only 0.55%.The analytical and experimental results show that the developed mechanism has good performances in both decoupling ability and load capability;its static and dynamic performance can be precisely estimated from corresponding analytical *** proposed mechanism has wide potentials in precision positioning applic

关键词： precision positioning flexure hinge dynamics decoupled structure

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Self-Triggered Set Stabilization of Boolean Control Networks and Its Applications

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1631-1642页

作者： Rong Zhao Jun-e Feng dawei zhang the School of Mathematics Shandong UniversityShandong UniversityJinan 250100China

Set stabilization is one of the essential problems in engineering systems, and self-triggered control(STC) can save the storage space for interactive information, and can be successfully applied in networked control systems with limited communication resources. In this study, the set stabilization problem and STC design of Boolean control networks are investigated via the semi-tensor product technique. On the one hand, the largest control invariant subset is calculated in terms of the strongly connected components of the state transition graph, by which a graph-theoretical condition for set stabilization is derived. On the other hand, a characteristic function is exploited to determine the triggering mechanism and feasible controls. Based on this, the minimum-time and minimum-triggering open-loop, state-feedback and output-feedback STCs for set stabilization are designed,respectively. As classic applications of self-triggered set stabilization, self-triggered synchronization, self-triggered output tracking and self-triggered output regulation are discussed as well. Additionally, several practical examples are given to illustrate the effectiveness of theoretical results.

关键词： Boolean control networks(BCNs) output regulation self-triggered control semi-tensor product of matrices set stabilization synchronization

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TOOTH CURVES AND ENTIRE CONTACT AREA IN PROCESS OF SPLINE COLD ROLLING

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Chinese Journal of Mechanical Engineering 2008年第6期21卷 94-97页

作者： zhang dawei LI Yongtang FU Jianhua School of Materials Science and Engineering Northwestern Polytechnical University Xi＇an 710072. China School of Materials Science and Engineering Taiyuan University of Science and Technology Taiyuan 030024 China

In spline rolling process, the contact area between roller and workpiece plays an important role in calculating rolling-force and rolling-moment. For the purpose of studying the contact area, contact state between roller and workpiece in process of spline cold rolling based upon cross rolling is analyzed. According to the suitable hypothesis, the mathematic model of roller-tooth-curve in optional position of rolling process is established. Combing the theory of conjugate curves with the theory of envelope curve, the corresponding mathematic model of workpiece-tooth-curve is established. By utilizing establishing mathematic models, the algorithm of entire contact area in rolling process is created. On the basis of the algorithm, calculation-program is compiled under MATLAB program language environment. The calculation-program actualizes quantitative analysis and quantitative calculation of contact areas. Utilizing the calculation-program, the influence of parameters on contact area is analyzed, and the tendency is consistent with the manufacturing experience. In consideration of rolling-force optimization, the primary process parameters may be selected according to results of calculation. The result of the present study may provide basis for research on rolling-force and rolling-moment.

关键词： Spline Cold rolling Contact area Mathematic model MATLAB

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Relationship between Hardness and Deformation during Cold Rolling Process of Complex Profles

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Chinese Journal of Mechanical Engineering 2023年第5期36卷 315-329页

作者： dawei zhang Linghao Hu Bingkun Liu Shengdun Zhao Xi’an Key Laboratory of Intelligent Equipment and Control School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China

The hardening on surface of complex profles such as thread and spline manufactured by cold rolling can efectively improve the mechanical properties and surface quality of rolled parts. The distribution of hardness in superfcial layer is closely related to the deformation by rolling. To establish the suitable correlation model for describing the relationship between strain and hardness during cold rolling forming process of complex profles is helpful to the optimization of rolling parameters and improvement of rolling process. In this study, a physical analog experiment refecting the uneven deformation during complex-profle rolling process has been extracted and designed, and then the large date set (more than 400 data points) of training samples refecting the local deformation characteristics of complexprofle rolling have been obtained. Several types of polynomials and power functions were adopted in regression analysis, and the regression correlation models of 45# steel were evaluated by the single-pass and multi-pass physical analog experiments and the complex-profle rolling experiment. The results indicated that the predicting accuracy of polynomial regression model is better in the strain range (i.e., ε 1.2) of training samples can be well described by power regression model;so the correlation relationship between strain and hardness during complex-profle rolling process of 45# steel can be characterized by a segmented function such as third-order polynomial in the range ε 1.2;and the predicting error of the regression model by segmented function is less than 10%.

关键词： Complex profle Cold rolling Multi passes Equivalent strain Vickers hardness

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Synthesis of comb bipolymers and their pour point depressing properties

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Petroleum Science 2014年第1期11卷 155-160页

作者： zhang Changqiao Gao Congcong Gao Fengfeng Wang Jian zhang dawei Wang Yan Xu dawei School of Chemistry and Chemical Engineering Shandong University Shandong Quality Certification Centre Shandong Product Quality Supervision & Inspection Research Institute

A bipolymer maleic anhydride-methyl acrylate （MAMA） was synthesized from maleic anhydride and methyl acrylate based on molecular *** further reacted with oleylamine or octadecyl alcohol to generate two comb polymers called Oleamide-MAMA （NMAMA） and OctadecanolMAMA （OMAMA）,*** structure of both the polymers was confirmed by their infrared spectral analysis （IR）,gel permeation chromatography analysis （GPC） and differential scanning calorimeter （DSC）.Moreover,the pour point depressing （PPD） properties of these comb polymers were examined *** results showed that besides the molecular weight and concentration of the polymers,the length of side chains and the number of functional groups also had great influence on the pour point depressing *** π bonds and hydrogen bonds between depressants were the key factors for improving the pour point depressing *** results suggest that both OMAMA and NMAMA are potential pour point depressants for industry.

关键词： Maleic anhydride comb polymers pour point depressant hydrogen bonds molecular simulation

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Design of an Automatic Autonomous Mini Prone-cone Microsatellite Docking Mechanism

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Chinese Journal of Mechanical Engineering 2010年第3期23卷 353-360页

作者： LAI Yinan DAI Ye TIAN Hao zhang dawei School of Mechanical and Power Engineering Harbin University of Science and Technology Harbin 150080 China Department of Astronautics andMechanics Harbin Institute of Technology Harbin 150001 China

The capability of docking, refueling, repairing, and updating microsatellites using automatic autonomous vehicles will be of significance critical value for design and operation of several space systems in the near feature. Automatic docking capability was successfully tested by many institutions such as National Space Development Agency in Japan, European Space Agency, National Aeronautics and Space Administration in USA, etc. However, there is still much more space for improvement of degree of automation during the process of docking with large deviations of the initial attitude. A novel automatic autonomous probe-cone docking mechanism used for microsatellite docking is proposed. This docking mechanism is designed according to the design indices such as miniaturization, degree of automation and automatic capture capability within large deviation of the initial attitude. On the basis of the virtual work principle, the dynamics modeling of the docking process is presented. The position of the contact point is then analyzed. Comprehensive system level simulation is conducted in the 13 kinds of typical operating conditions with the initial deviations. Capture performance is analyzed. The simulation results show that the docking mechanism can be smoothly captured within 2 s in all cases of large attitude deviation between the active and passive spacecrafts. A virtual prototype model of the docking mechanism is established through ADAMS for further verifying the correctness of the buffer parameter model and the autonomous docking capability. A laboratory platform is designed for on-the-ground experimental validation of the property of mini probe-cone docking mechanism. Repeated docking tests prove the proposed design of the mini probe-cone docking mechanism system for its high reliability, and automatic capture capability within large attitude range. The kinetic model of the docking capture process and the mechanism structure could provide some references for similar m

关键词： docking mechanism numerical simulation virtual prototype capture buffer parameter

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Characteristics of surface and subsurface of formed thread parts by axial-infeed thread rolling process

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Chinese Journal of Aeronautics 2023年第3期36卷 471-481页

作者： Shuowen zhang dawei zhang Shengdun ZHAO Fei JIANG Myoung-Gyu LEE Xi’an Key Laboratory of Intelligent Equipment and Control School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China Department of Materials Science and Engineering Seoul National University08826 SeoulRepublic of Korea

The thread rolling process has been widely applied to manufacture high-performance thread *** this process,the evolutions of surface and subsurface are frequently introduced,which affect the working performance of manufactured *** this study,an axial-infeed thread rolling process(ATRP)is employed,and the macro-meso surface characteristics under different lubrications and operating conditions are ***,the distributions of microstructure and hardness on the subsurface of formed tooth are analyzed in detail,along with the study of stress state and yield strength *** is found that the MoS_(2)grease is more effective in reducing the surface roughness and defects than the lubrication oil and water-base graphite during the ATRP *** rolling speed improves the quality of surface morphology and can reduce the surface *** the subsurface of bottom and flank,intensive shear stress occurs in a narrow region,resulting in the elongation and refinement of the grains and increasing the low angle grain boundary *** on the grain size and plastic strain,the yield strength is *** maximum yield strength and hardness on the bottom of formed tooth are improved by 41.2% and 39.4%,respectively.

关键词： ATRP Lubrication Surface characteristics Microstructure distribution Hardness improvement Grain size

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