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Numerical study on fatigue damage properties of cavitation erosion for rigid metal materials

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Journal of University of Science and Technology Beijing 2008年第3期15卷 261-266页

作者： Guogang Wang Guang Ma dongbai sun Hongying Yu Huimin Meng School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Power Station Technology Division China Electric Power Research Institute Beijing 100070 China

Cavitation erosion is an especially destructive and complex phenomenon. To understand its basic mechanism, the fatigue process of materials during cavitation erosion was investigated by numerical simulation technology. The loading spectrum used was generated by a spark-discharged electrode. Initiation crack life and true stress amplitude was used to explain the cavitation failure period and damage mechanism. The computational results indicated that the components of different materials exhibited various fatigue lives under the same external conditions. When the groove depth was extended, the initiation crack life decreased rapidly, while the true stress amplitude was increased simultaneously. This gave an important explanation to the accelerating material loss rate during cavitation erosion. However, when the groove depth was fixed and the length varied, the fatigue life became complex, more fluctuant than that happened in depth. The results also indicate that the fatigue effect of cavitation plays an important role in contributing to the formation and propagation of characteristic pits.

关键词： cavitation erosion microjet numerical simulation fatigue analysis crack initiation loading spectrum

Preparation of IrO_2+MnO_2 coating anodes and their application in NaClO production

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Journal of University of Science and Technology Beijing 2008年第4期15卷 461-467页

作者： Yongle Ni Huimin Meng Dong Chen dongbai sun Hongying Yu School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

To improve the durability as well as to reduce the cost of anodes, the IrO2＋MnO2 composite coating anodes for NaCIO production were prepared by thermal decomposition. Scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDX）, and X-ray diffraction analysis （XRD） were carried out to investigate the morphologies, element distribution, and microstructure. The anodic polarization curves were employed to study the effect of sintering temperature on the Cl2 evolution reaction （CER） of the electrodes. The accelerated life tests （ALT） and electrochemical impedance spectroscopy measurement （EIS） were utilized to investigate the stability. The rules of NaCIO production were also studied by the static electrolysis experiment. The results indicate that sintering temperature has a significant influence on the CER properties as well as the ALT values of the electrodes. The electrode prepared at 400℃ has the best CER properties and the longest ALT value.

关键词： iridium dioxide manganese dioxide sodium hypochlorite chlorine evolution stability impedance spectroscopy measurement (EIS)

MIDNet:Deblurring Network for Material Microstructure Images

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Computers, Materials & Continua 2024年第4期79卷 1187-1204页

作者： Jiaxiang Wang Zhengyi Li Peng Shi Hongying Yu dongbai sun National Center for Materials Service Safety University of Science and Technology BeijingBeijing100083China School of Materials Sun Yat-Sen UniversityShenzhen518107China School of Materials Science and Engineering Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Sun Yat-Sen UniversityGuangzhou510006China

Scanning electron microscopy(SEM)is a crucial tool in the field of materials science,providing valuable insightsinto the microstructural characteristics of ***,SEM images often suffer from blurrinesscaused by improper hardware calibration or imaging automation errors,which present challenges in analyzingand interpretingmaterial ***,rectifying the blurring of these images assumes paramountsignificance to enable subsequent *** address this issue,we introduce a Material Images DeblurringNetwork(MIDNet)built upon the foundation of the Nonlinear Activation Free Network(NAFNet).MIDNetis meticulously tailored to address the blurring in images capturing the microstructure of *** keycontributions include enhancing the NAFNet architecture for better feature extraction and representation,integratinga novel soft attention mechanism to uncover important correlations between encoder and decoder,andintroducing newmulti-loss functions to improve training effectiveness and overallmodel *** conducta comprehensive set of experiments utilizing the material blurry dataset and compare them to several state-of-theartdeblurring *** experimental results demonstrate the applicability and effectiveness of MIDNet in thedomain of deblurring material microstructure images,with a PSNR(Peak Signal-to-Noise Ratio)reaching 35.26 dBand an SSIM(Structural Similarity)of *** dataset is available at:https://***/woshigui/MIDNet.

关键词： Image deblurring material microstructure attention mechanism deep learning

Tunable emission properties of core-shell ZnCuInS-ZnS quantum dots with enhanced fluorescence intensity

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Journal of Materials Science & Technology 2018年第6期34卷 942-948页

作者： Yihe Jia Haicheng Wang Long Xiang Xiaoguang Liu Wei Wei Ning Ma dongbai sun National Center for Materials Service Safety University of Science and Technology Beijing Beijing 100083 China Department oflnorganic Nonmetallic Materials School of Materials Science and Engineering University of Science and Technology Beijing 100083 Beijing China College of Materials Science and Chemical Engineering Harbin Engineering University Harbin 150001 China

Cadmium-free Ⅰ-Ⅲ-Ⅵ quantum dots （QDs）, represented by Cu-In-S （CIS）, are widely investigated for their non-toxicity and tunable emission properties. In this work, Zn-Cu-In-S （ZCIS） alloyed QDs were synthesized via a solvothermal approach by heating up a mixture of the corresponding metal precursors and sulphur powder with dodecanethiol in oleylamine media, and the fluorescent intensity was greatly enhanced by coating ZnS （ZS） shell. By changing the ratio of Cu, the as prepared ZCIS-ZS QDs showed composition-tunable photoluminescent （PL） emission over the visible spectral window from about 500 nm to 620 rim, which is much wider than that of CIS QDs. Moreover, the influence of excitation wavelength, reaction temperature and time on the optical properties of the ZCIS-ZS QDs was also studied. This research provides a feasible and simple approach to prepare ZCIS-ZS QDs with large tunable spectral range on visible region, which could greatly contribute to the development of potential applications due to their non-toxicity and excellent optical properties.

关键词： Emission property ZnCulnS Quantum dots Fluorescence intensity

Wear characteristics of spheroidal graphite roll WC-8Co coating produced by electro-spark deposition

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Rare Metals 2010年第2期29卷 174-179页

作者： WANG Jiansheng, MENG Huimin, YU Hongying, FAN Zishuan, and sun dongbai School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China School of Materials Science and Engineering University of Science and Technology Beijing Beijing China

Electro-spark deposition（ESD） was adopted for preparing high property coatings by depositing WC-8Co cemented carbide on an spheroidal graphite roll *** microstructure and properties of the coating were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM） with energy dispersive X-ray（EDX） and ball-disc configuration wear *** results show that nanosized particles and amorphous structures prevail in the coating which is metallurgically bonded to the *** microstructures of the transition zone include columnar structure and equiaxed *** primary phases of the coating contain W2C, W6C2.54, Fe3W3C, and *** results of abrasive test show that the coating has low friction coefficients（μaverage = 0.18） and the wear mechanisms are mainly abrasive wear, fatigue wear, and oxidation *** maximum microhardness value of the coating is about 17410 N/*** study reveals that the electro-spark deposition process has better coating quality and the coating has high wear resistance and hardness.

关键词： electro-spark deposition WC/Co coatings wear resistance microstructure

Galvanic effects on cavitation damage for 1Cr13 stainless steel

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Journal of University of Science and Technology Beijing 2003年第4期10卷 33-37页

作者： dongbai sun, Xia Bai, Hongying Yu, Huimin Meng, and Huiqing LiUNDP-Beijing Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China UNDP Corrosion Ctr. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Based on the electric-spark principle, a new kind of cavitation damagetesting apparatus was designed, which could produce the bubble. Bubbles collapsed and acted on asmall surface area of the alloy surface, so an intensive electrochemical inhomogenous state would beinduced and lead to the existence of surface galvanic effect on the alloy. The galvanic effect of1Cr13 SS during cavitation damage has been quantitatively investigated in NaCl solution. The resultsshow that intensive galvanic effect of 1Cr13 SS during cavitation damage appears the potential ofthe damaged area shifting negatively with the bubble collapse and simultaneously the galvaniccurrent generates. The mass loss of alloy due to cavitation increases with the bubble quantity, andincreases with the increasing of Cl- content. And both the total mass loss and the mass loss due togalvanic corrosion increase linearly with the area ratio of cavitation damaged to undamaged *** surface galvanic effects speed up the dissolution rate of the alloy, which, in turn,accelerates the mechanical damage, and aggravates the mass loss of the alloy. It has been furtherconfirmed that the mass loss due to the surface galvanic effect can be decreased by catholicprotection.

关键词： cavitation damage galvanic effect area ratio mass loss

Surface hardening of Fe-based alloy powders by Nd:YAG laser cladding followed by electrospark deposition with WC-Co cemented carbide

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Rare Metals 2010年第4期29卷 380-384页

作者： WANG Jiansheng,MENG Huimin,YU Hongying,FAN Zishuan,and sun dongbai School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China School of Materials Science and Engineering University of Science and Technology Beijing Beijing China

This paper presents the results of a study concerned with the surface hardening of Fe-based alloys and WC-8Co cemented carbide by inte- grating laser cladding and the electrospark deposition processes. Specimens of low carbon steel were processed firstly by laser cladding with Fe-based alloy powders and then by electrospark deposition with WC-SCo cemented carbide. It is shown that, for these two treatments, the electrospark coating possesses finer microstructure than the laser coating, and the thickness and surface hardness of the electrospark coating can be substantially increased.

关键词： laser cladding electrospark deposition surface hardening Fe-based alloy cemented carbide

Effects of complexing agents on acidic electroless nickel deposition

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Rare Metals 2010年第4期29卷 401-406页

作者： JIN Ying YU Hongying YANG Dejun sun dongbai National Center for Materials Service Safety University of Science and Technology Beijing Beijing 100083 China Corrosion andProteetion Center School of Materials Science andEngineering University of Science and Technology Beijing Beij'ing 100083 China

Our previous study reported the influences of different complexing agents on electroless nickel （EN） by examining the properties of the deposits. In the present work, the effects of four common-used complexing agents on EN deposition rate and the stability of solution pH values were examined, either with an acetic pH buffer agent or absent of them. It is indicated that the pH buffeting effect of them is dominative when the EN solution is lack of the pH buffer. Under this situation, the EN deposition rate increases with the concentration of complexing agents increasing. The EN deposition rate decreases with fin＇ther adding the complexing agent when the solution already has enough pH buffer capability. Electrochemical impedance spectroscopy obtained during EN deposition illustrates that, in this case, the enhanced reaction resistance is the main reason for a lower deposition rate. However, the influence of polarization caused by mass transfer is not negligible at high complex ratio for sodium citrate and malic acid EN solutions.

关键词： electroless nickel complexing agents electrochemical impedance spectrum reaction resistance pH value

Future Performance Prediction of Research Infrastructure Based on Past Performance

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Journal of Donghua University(English Edition) 2018年第4期35卷 336-338页

作者： WU Di PENG Rui sun dongbai XU Wenchao QIAO Lili Shool of Management Xi＇an Jiao tong UniversityXi＇an 710049China Donlinks School of Economics ＆Management University of Science ＆ Technology BeijingBeijing 100083China National Center for Materials Service Safety University of Science ＆ Technology BeijingBeijing 100083China

Research infrastructure is crucial for development of research,and thus the evaluation of its performance is ***,existing researches mostly focus on its past observations,lacking of a prediction for future. In this paper, procedures are proposed to predict the distribution for the number of papers published in a certain future year. The publication reliability,which is defined as the probability that the number of published papers in the future year is bigger than a pre-specified number,is evaluated. Illustrative examples are proposed to show the applications of the model.

关键词： research infrastructure performance prediction reliability