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Cyclic oxidation behavior of NiCoCrAlY/YSZ@Ni composite coatings fabricated by laser cladding

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Journal of Iron and Steel Research International 2020年第10期27卷 1226-1235页

作者： hai-zhong zheng Pei-feng Zhou Gui-fa Li Ping Peng School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Material Science and Engineering Nanchang Hangkong UniversityNanchang 330063JiangxiChina School of Material Science and Engineering Hunan UniversityChangsha 410082HunanChina

Composite coating on GH4169 alloy is prepared by laser cladding yttria-stabilized zirconia(YSZ)@Ni core-shell powdersmixed with NiCoCrAlY alloy *** cyclic oxidation behavior of the coatings,especially the growth process of theoxide layer,is investigated based on experimental research and first-principle *** results indicate that theoxidation resistance of coated GH4169 alloy is beer than that of uncoated GH4169 *** coating has three layers:acellular dendrite outer layer,a planar YSZ interlayer,and an inner layer composed of Cr2O3 formed during laser *** oxidation at 1000 and 1050℃,as the oxidation time increases,the cellular dendrite outer layer becomes thicker,andthe planar yttria-stabilized zirconia interlayer becomes *** the planar interlayer and Cr2O3 inner layer,and Al2O3 layer ***,cracks formed in the intcrface of Al2O3/Cr2O3 owing to thcir weak interface strength,whichled to the failure of the composite coating.

关键词： Laser cladding NiCoCrAlY/YSZ@Ni composite coating Cyelic oxidation-Oxidation mechanism.Crack nucleation

How Machine Learning Accelerates the Development of Quantum Dots?

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Chinese Journal of Chemistry 2021年第1期39卷 181-188页

作者： Jia Peng Ramzan Muhammad Shu-Liang Wang hai-zheng zhong MIIT Key laborotory for Low-Dimensional Quantum Structure and Devices School of Materials Sciences&EngineeringBeiing Institute of Technology100081 BeijingChina School of Computer Science&Technology Beijing Institute of TechnologyBeijing 100081China

With the rapid developments in the field of information technology,the material research society is looking for an alternate scientific route to the traditional methods of trial and error in material research and process *** learning emerges as a new research paradigm to accel-erate the application-oriented material *** dots are ex-panded as functional nanomaterials to enhance cutting-edge photonic ***,they suffer from uncertainty in industrial fabrication and ***,we discuss how machine learning accelerates the development of quantum *** basic principles and operation proce-dures of machine learning are described with a few representative examples of quantum *** emphasize how machine learning contributes to the optimization of synthesis and the analysis of material *** conclude,we give a short perspective discussing the problems of combining machine learning and quantum dots.

关键词： Quantum dots Machine learning Materials genome initiative Neural networks On-demand

Effect of shot peening on microstructure,nanocrystallization and microhardness of Ti-10V-2Fe-3Al alloy surface

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Journal of Iron and Steel Research International 2019年第1期26卷 52-58页

作者： hai-zhong zheng Sheng-hua Guo Qin-hao Luo Xiao-yong Shu Gui-fa Li National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology Nanchang Hangkong UniversityNanchang 330063JiangxiChina

Severe plastic deformation of Ti-10V-2Fe-3Al alloy in the surface region was caused by shot peening at air pressure of 0.6 MPa with processing time ranging from 1 to 45 *** results showed that the thickness of surface deformation layer was proportio nal to the processing time,the microhardness of the shot-peened surface in creased from 280 to 385 HV,and the depth of highly hardening layers arrived at 200μ*** was worth noting that a grain size gradient from nanocrystalline on the surface toward coarse grain in the matrix was obtained during the shot peening process and the minimum grain size in the top surface after shot peening was about 100-200 nm.

关键词： Ti-10V-2Fe-3Al alloy Shot peening treatment Surface nanocrystallization Martensitic transformation Microhardness

Rapid Growth of Halide Perovskite Single Crystals:From Methods to Optimization Control

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Chinese Journal of Chemistry 2019年第6期37卷 616-629页

作者： Yu-Ling Wang Shuai Chang Xiao-Mei Chen Yan-Dong Ren Li-Fu Shi Yong-Hao Liu hai-zheng zhong School of Mechatronics Engineering Daqing Normal UniversityXibin Xi RoadRanghulu DistrictDaqingHeilongjiang 163712China Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems School of Materials Science&EngineeringBeijing Institute of TechnologyZhongguancun South StreetHaidian DistrictBeijing 100081China

Metal halide perovskites are emerging as new generation optoelectronic materials due to their high carrier mobility, long carrier diffusion length and large light absorption coefficient, which have broad applications in solar cell, light-emitting diode, laser, photodetector and transistors. Perovskite single crystal is an ideal platform for discerning the intrinsic properties of these materials. In some cases, perovskite single crystals are better candidates to gain high performance optoelectronics. However, the growth of perovskite single crystals is time and cost consuming, which has an obvious disadvantage for device exploration. Therefore, fast growth technique is highly desirable in not only promoting the use of perovskites in commercial applications but also facilitating deep physical investigation of the materials. In this review, we summarize thoroughly the development of fast growth of the halide perovskites single crystal. Specifically, we highlight the progress of rapid growth techniques with emphasis on the optimization control.

关键词： crystal growth semiconductors synthetic methods metal halide perovskite single crystals rapid growth

Influence of surface charges on the emission polarization properties of single CdSe/CdS dot-in-rods

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Frontiers of physics 2019年第6期14卷 73-82页

作者： Guo-Feng Zhang Chang-Gang Yang Yong Ge Yong-Gang Peng Rui-Yun Chen Cheng-Bing Qin Yan Gao Lei Zhang hai-zheng zhong Yu-Jun zheng Lian-Tuan Xiao Suo-Tang Jia State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser Spectroscopyand Collaborative Innovation Center of Extreme OpticsShanxi UniversityTaiyuan 030006China Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China School of Physics Shandong UniversityJinan 250100China

We report an experimental investigation of the influence of surface charges on the emission polarization properties of single CdSe/CdS dot-in-rods(DRs),which is important for their polarization-based practical *** covering the single DRs with N-type semiconductor indium tin oxide(ITO)nanoparticles,the surface of single DRs is charged by ITO through interracial electron *** is confirmed by the experimental observations of the reduced photoluminescence intensities and lifetimes as well as the suppressing *** is found that the full width at half maximum of histogram of polarization degrees of the single DRs is broadened from 0.24(on glass)to 0.41(in ITO).In order to explain the exprimental results,the band-edge exciton fine structure of single DRs is calculated by taking into account the sample parameters,the emission polarization,and the surface *** calculation results show that the level ordering of the emitting states determines the polarization degrees tending to increase or decrease under the influence of surface *** surface electrons can induce an increase in the spacing between the emitting levels to change the populations and thus change the polarization *** addition,different numbers of surface electrons may randomly distribute on the long CdSe/CdS rods,leading to the heterogeneous influences on the single DRs causing the broadening of polarization degrees also.

关键词： single CdSe/CdS dot-in-rods polarization properties surface charges band-edge exciton fine structure

Vibration test and numerical analysis of loess slope site under high-speed train loading condition

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Yantu Lixue/Rock and Soil Mechanics 2020年 41卷 333-344页

作者： zheng, hai-zhong Yan, Wu-Jian Shi, Yu-Cheng Wang, Ping Xu, Shi-Yang Tian, Wen-Tong Key Laboratory of Loess Earthquake Engineering Lanzhou Institute of Seismology CEA Lanzhou 730000 China Geotechnical Disaster Prevention Engineering Technology Research Center of Gansu Province Lanzhou 730000 China

In order to study the site effect of loess stepped slope under the train loading condition, the field test was carried out on the stepped slope of a specific embankment section of Tongwei-Qin'an line which belongs to Baoji-Lanzhou special passenger line. Based on the time and frequency domain analysis of the measured vibration signals, the site effect of loess stepped slope and the train speed impacts on the site vibration are studied. Based on the Hilbert-Huang transform, the vibration of train, track and the movement state of the train are analyzed. Based on the field investigation, three different types of slope models are established by using finite element software, and the dynamic response of different types of slope site under the train load is analyzed. The results show that the peak acceleration tends to attenuate with the increase of the distance from the track center, but there is an obvious vibration rebound at the fourth terrace. The vibration frequency of each test point is mainly concentrated in 5-90 Hz, and the spectrum characteristics of each test point are obviously different. With the increase of distance from the track center, the main vibration frequency moves from high frequency to low frequency. The peak acceleration and vibration acceleration levels at each terrace are not only controlled by train speed, but also affected by topographic and geomorphological characteristics. The acceleration nephograms of three different slopes at the same time are different. Besides, the difference between vibration acceleration peak value and displacement peak value at three slopes in the horizontal direction is very large, but the difference in the vertical direction is small. © 2020, Science Press. All right reserved.

关键词： Hilbert-Huang transform

合金元素Al对Cr-20Nb合金高温抗氧化性能的影响

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航空材料学报 2009年第6期29卷 8-12页

作者：黄毅鲁世强郑海忠南昌航空大学材料科学与工程学院南昌330063

采用机械合金化+热压烧结工艺制备了掺杂合金元素Al的Cr-20Nb合金,研究Al对Cr-20Nb合金在1100℃和1200℃下高温抗氧化性的影响。结果表明,合金元素Al能促进Cr-20Nb合金氧化时生成AlNbO4复合型氧化物,该复合型氧化物能有效抑制Cr2O3的挥... 详细信息

采用机械合金化+热压烧结工艺制备了掺杂合金元素Al的Cr-20Nb合金,研究Al对Cr-20Nb合金在1100℃和1200℃下高温抗氧化性的影响。结果表明,合金元素Al能促进Cr-20Nb合金氧化时生成AlNbO4复合型氧化物,该复合型氧化物能有效抑制Cr2O3的挥发反应,从而改善Cr2O3氧化层的致密性,并提高氧化膜的粘附性,导致合金抗氧化性显著提高。不同Al含量的Cr-20Nb合金氧化增重均近似于抛物线规律。

关键词： Cr-20Nb合金合金元素Al 高温抗氧化

Dynamic spheroidization kinetics behavior of Ti-6.5Al-2Zr-1Mo-1V alloy with lamellar microstructure

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Transactions of Nonferrous Metals Society of China 2016年第5期26卷 1301-1309页

作者：董显娟鲁世强郑海忠南昌航空大学航空材料热加工技术航空科技重点实验室南昌330063 南昌航空大学航空制造工程学院南昌330063 南昌航空大学材料科学与工程学院南昌330063

Abstract： The dynamic spheroidization kinetics behavior of Ti-6.5Al-2Zr-1Mo-1V alloy with a lamellar initial microstructure was studied by isothermal hot compression tests in the temperature range of 750-950℃ and strain rates of 0.001-10 s^-1. The results show that the spheroidized fraction of alpha lamellae increases with the increase of temperature and the decrease of strain rate. The spheroidization kinetics curves predicted by JMAK equation agree well with experimental ones. The corresponding SEM and TEM observations indicate that the dynamic spheroidization process can be divided into two stages. The primary stage is boundary splitting formed by two competing mechanisms which are dynamic recrystallization and mechanical twin. In the second stage, the penetration of beta phase into the alpha/alpha grain boundaries is dominant, which is controlled in nature by diffusion of the chemical elements such as Al, Mo and V.

关键词： titanium alloy lamellar microstructure spheroidization kinetics equation

热压烧结对Laves相NbCr2合金组织及高温氧化行为的影响

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材料热处理学报 2009年第1期30卷 40-44页

作者：郑海忠鲁世强周善民南京航空航天大学材料科学与技术学院江苏南京210016 南昌航空大学材料科学与工程学院江西南昌330063

研究了不同热压温度和时间对Cr-33at%Nb合金显微组织及氧化行为的影响,并用SEM和X射线衍射对合金组织及氧化产物进行了分析。结果表明,热压温度升高有利于组织致密,保压时间延长有利于Laves相NbCr2热反应合成。不同热压条件制备的Cr-Nb... 详细信息

研究了不同热压温度和时间对Cr-33at%Nb合金显微组织及氧化行为的影响,并用SEM和X射线衍射对合金组织及氧化产物进行了分析。结果表明,热压温度升高有利于组织致密,保压时间延长有利于Laves相NbCr2热反应合成。不同热压条件制备的Cr-Nb合金在1200℃的氧化动力学均近似符合抛物线规律,氧化膜均由两部分组成,外层为Cr2O3,内层为CrNbO4。随着热压温度的升高,合金氧化速率减小;保压时间由15min延长到80min时,合金氧化速率逐渐减小,但当达到120min时,氧化速率又有所提高。

关键词： Laves相NbCr2 热压参数显微组织氧化行为