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Core-shell structure nanoprecipitates in Fe-xCu-3.0Mn-1.5Ni-1.5Al alloys: A phase field study

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Progress in Natural Science:Materials International 2022年第3期32卷 358-368页

作者： yuhong zhao Yuanyang Sun Hua Hou School of Materials Science and Engineering North University of China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and Technology University of Science and Technology Beijing College of Materials Science and Engineering Taiyuan University of Science and Technology

The core-shell structure precipitatates of Fe-xCu-3.0Mn-1.5Ni-1.5Al alloys under internal and external strain was investigated by using a multicomponent continuous phase field model based on Gibbs free energy of sub regular solution. Results show that the early cluster nuclei are not pure Cu, and Mn/Ni/Al also gather in the same position of Cu rich nuclei, resulting in four core-shell structures in precipitation. In the absence of external strain, the morphology of precipitates is mainly determined by interfacial energy, intrinsic elastic anisotropy and lattice distortion between new phase and parent phase. Intrinsic elastic strain energy can inhibit precipitation, while has no obvious effect on particle morphology. In coarsening, the elastic energy decreases due to the combination of particles. The loading direction and magnitude of the applied elastic strain field can control the morphology of precipitates. The external strain and the interaction between Mn, Ni and Al promote the joining and merging of adjacent core-shell particles. This work has guiding significance for the design of Fe-x Cu-3.0Mn-1.5Ni-1.5Al alloys and other core-shell precipitates materials.

关键词： Phase-field Fe–Cu–Mn–Ni–Al Core-shell structure Elastic strain

Machine Learning-Based Research on Tensile Strength of SiC-Reinforced Magnesium Matrix Composites via Stir Casting

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 453-466页

作者： Zhihong Zhu Wenhang Ning Xuanyang Niu yuhong zhao Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Collaborative Innovation Center of Ministry of Education and Shanxi Province for High-Performance Al/Mg Alloy MaterialsNorth University of ChinaTaiyuan 030051China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

SiC is the most common reinforcement in magnesium matrix composites,and the tensile strength of SiC-reinforced magnesium matrix composites is closely related to the distribution of *** a uniform distribution of SiC requires fine control over the parameters of SiC and the processing and preparation ***,due to the numerous adjustable parameters,using traditional experimental methods requires a considerable amount of experimentation to obtain a uniformly distributed composite ***,this study adopts a machine learning approach to explore the tensile strength of SiC-reinforced magnesium matrix composites in the mechanical stirring casting *** analyzing the influence of SiC parameters and processing parameters on composite material performance,we have established an effective predictive ***,six different machine learning regression models have been developed to predict the tensile strength of SiC-reinforced magnesium matrix *** validation and comparison,our models demonstrate good accuracy and reliability in predicting the tensile strength of the composite *** research findings indicate that hot extrusion treatment,SiC content,and stirring time have a significant impact on the tensile strength.

关键词： Machine learning Stirring casting Magnesium matrix composite Tensile strength

Microstructure evolution and grain refinement mechanism of rapidly solidified single-phase copper based alloys

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Journal of Materials Science & Technology 2022年第33期128卷 160-179页

作者： Xiaolong Xu Cheng Tang Hongfu Wang Yukang An yuhong zhao College of Materials Science and Engineering School of Mechanical EngineeringNorth University of ChinaTaiyuanShanxi 030051China

The Cu65Ni35,Cu60Ni40 and Cu55Ni45 alloys were undercooled by fluxing method,and the rapid solidification structure with different undercoolings were also *** the same time,the interface migration process during rapid solidification was photographed by high-speed photography,and the relationship between the morphological characteristics of solidification front and undercooling was *** microstructures of the three alloys were observed by metallographic microscope,and the microstructure characteristics and evolution law were systematically *** was found that two grain refinement events occurred in the low undercooling range and high undercooling range,*** EBSD test of grain refined microstructures showed that the microstructure in the low undercooling range has a high proportion of low-angle grain boundaries and high strength ***,there were a large proportion of high-angle grain boundaries and a high proportion of twin grain boundaries and more randomly oriented grains in the microstructure in the high undercooling *** TEM test of the Cu55Ni45 alloy with the maximum undercooling of 284 K showed that there were high-density dislocation networks and stacking faults in the ***,the evolution relationship between microstructure hardness and undercooling was systematically *** was found that the microhardness of the three alloys decreased sharply near the critical *** with EBSD,TEM and microhardness analysis,it was confirmed that the grain refinement under low undercooling was caused by dendrite remelting,while the grain refinement under high undercooling was caused by stress-induced recrystallization.

关键词： Rapid solidification structure Grain refinement Dendrite remelting Recrystallization

An Improved Algorithm of Nonlinear RED Based on Membership Cloud Theory

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Chinese Journal of Electronics 2017年第3期26卷 537-543页

作者： zhao yuhong MA Zhonggui ZHENG Xuefeng TU Xuyan School of Information Engineering Inner Mongolia University of Science and Technology School of computer and communication Engineering University of Science and Technology Beijing

Concerning on the shortcoming and complexity of Random early detection(RED)algorithm in network congestion control,a new RED algorithm based on the Hemi-Rise Cloud model(CRED)was proposed,nonlinear packet loss strategy was used,and sensitivity and uncertainty of parameters were *** a result,queue length could be kept stable in the neighborhood of reference *** congestion was well controlled and network resource was used *** stability of the algorithm was studied and the experimental results showed that the proposed algorithm could improve the stability,and had better performance than the RED and Adaptive RED(ARED)algorithms.

关键词： RED Nonlinear Hemi-rise cloud model Membership degree NS2

First Principles Calculations for Corrosion in Mg-Li-Al Alloys with Focus on Corrosion Resistance: A Comprehensive Review

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Computers, Materials & Continua 2024年第11期81卷 1905-1952页

作者： Muhammad Abdullah Khan Muhammad Usman yuhong zhao School of Materials Science and Engineering Collaborative Innovation Center of Ministry of Education and Shanxi Province for High-Performance Al/Mg Alloy MaterialsNorth University of ChinaTaiyuan030051China Electronics Department North University of ChinaTaiyuan030000China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang110004China

This comprehensive review examines the structural,mechanical,electronic,and thermodynamic properties of Mg-Li-Al alloys,focusing on their corrosion resistance and mechanical performance *** first-principles calculations based on Density Functional Theory(DFT)and the quasi-harmonic approximation(QHA),the combined properties of the Mg-Li-Al phase are explored,revealing superior incompressibility,shear resistance,and stiffness compared to individual *** review highlights the brittleness of the alloy,supported by B/G ratios,Cauchy pressures,and Poisson’s *** structure analysis shows metallic behavior with varied covalent bonding characteristics,while Mulliken population analysis emphasizes significant electron transfer within the *** paper also studied thermodynamic properties,including Debye temperature,heat capacity,enthalpy,free energy,and entropy,which are precisely examined,highlighting the Mg-Li-Al phase sensitive to thermal conductivity and thermal performance *** density of states(PHDOS)confirms dynamic stability,while anisotropic sound velocities reveal elastic *** comprehensive review not only consolidates the current understanding of the Mg-Li-Al alloy’s properties but also proposes innovative strategies for enhancing corrosion *** these strategies is the introduction of a corrosion barrier akin to the Mg-Li-Al network,which holds promise for advancing both the applications and performance of these *** review serves as a crucial foundation for future research aimed at optimizing alloy design and processing methods.

关键词： First-principles calculations Mg-Li-Al alloys corrosion resistance thermodynamic properties mechanical properties

Numerical simulation of an acoustic field generated by a phased arc array in a fluid-filled cased borehole

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Petroleum Science 2014年第3期11卷 385-390页

作者： Che Xiaohua Qiao Wenxiao Wang Ruijia zhao yuhong State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum Key Laboratory of Earth Prospecting and Information Technology China University of Petroleum China National Oil & Gas Exploration & Development Company

Transducers that are widely applied in cement bond evaluation tools, such as cement bond logs and variable density logs, cannot radiate acoustic energy directionally because of the characteristics of monopole sources. A phased arc array transmitter, which is a novel transducer that differs from monopole and dipole transducers, is presented in this study. To simulate the acoustic field generated by a phased arc array in a fluid-filled cased borehole with different channelings, a 3D finite-difference time-domain method is adopted. The acoustic field generated by a traditional monopole source is also simulated and compared with the field generated by the phased arc array transmitter. Numerical simulation results show that the phased arc array radiates energy directionally in a narrow angular range in the borehole, thereby compressing the acoustic energy into a narrow range in the casing pipe, the cement, and the formation. We present the analyses of first-arrival waveforms and the amplitudes of casing waves at different azimuthal angles for the two different sources. The results indicate that employing a directional source facilitates azimuthal identification and analysis of possible channeling behind the casing pipe.

关键词： Phased arc array azimuthal angle first-arrival amplitude acoustic field cased borehole

Paraelectric Doping Simultaneously Improves the Field Frequency Adaptability and Dielectric Properties of Ferroelectric Materials:A Phase-Field Study

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Computers, Materials & Continua 2024年第10期81卷 213-228页

作者： Zhi Wang Jinming Cao Zhonglei Liu yuhong zhao School of Materials Science and Engineering Collaborative Innovation Center of Ministry of Education and Shanxi Province for High-Performance Al/Mg Alloy MaterialsNorth University of ChinaTaiyuan030051China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang110004China

Recent years,the polarization response of ferroelectrics has been entirely ***,it is found that the polarization may disappear gradually with the continually applied of electric *** this paper,taking K0.48Na0.52NbO3(KNN)as an example,it was demonstrated that the residual polarization began to decrease when the electric field frequency increased to a certain extent using a phase-field *** results showed that the content of out-of-plane domains increased first and then decreased with the increase of applied electric field frequency,the maximum polarization disappeared at high frequencies,and the hysteresis loop became *** order to further study the abnormal changes of hysteresis loops of ferroelectrics under high electric field frequency,we analyzed the hysteresis loop and dielectric response of solid solution 0.1SrTiO_(3)-0.9K_(0.48)Na_(0.52)NbO_(3).It was found that the doped hysteresis loop maintained its shape at higher frequency and the dielectric constant *** kind of doping has a higher field frequency adaptability,which has a key guiding role in improving the dielectric properties of ferroelectric thin films and expanding the frequency application range of ferroelectric nano memory。

关键词： Ferroelectric ceramics dielectric properties electric field frequency doping phase field method

Phase-field simulation for the evolution of solid/liquid interface front in directional solidification process

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Journal of Materials Science & Technology 2019年第6期35卷 1044-1052页

作者： yuhong zhao Bing Zhang Hua Hou Weipeng Chen Meng Wang College of Materials Science and Engineering North University of China Taiyuan 030051 China State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xian 710072 China

In this study, the phase field method was used to study the multi-controlling factors of dendrite growth in directional solidification. The effects of temperature gradient, propelling velocity, thermal disturbance and growth orientation angle on the growth morphology of the dendritic growth in the solid/liquid interface were discussed. It is found that the redistribution of solute leads to multilevel cavity and multilevel fusion to form multistage solute segregation, and the increase of temperature gradient and propelling velocity can accelerate the dendrite growth of directional solidification, and also make the second dendrites more developed, which reduces the primary distance and the solute segregation. When the temperature gradient is large, the solid-liquid interface will move forward in a flat interface mode,and the thermal disturbance does not affect the steady state behavior of the directionally solidified dendrite tip. It only promotes the generation and growth of the second dendrites and forms the asymmetric dendrite. Meanwhile, it is found that the inclined dendrite is at a disadvantage in the competitive growth compared to the normal dendrite, and generally it will disappear. When the inclination angle is large, the initial primary dendrite may be eliminated by its secondary or third dendrite.

关键词： Phase field method Directional solidification Interface morphology Multi-control factors

Total phenols, flavonoids, and procyanidins levels and total antioxidant activity of different Korean pine(Pinus koraiensis) varieties

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Journal of Forestry Research 2019年第5期30卷 1743-1754页

作者： Sitong Zhang Ligang Zhang Lu Wang yuhong zhao School of Forestry Northeast Forestry UniversityHarbin 150040People’s Republic of China Food College Northeast Agricultural UniversityHarbin 150030People’s Republic of China School of Chemical Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Total phenols,flavonoids,procyanidins,and total antioxidant capacity,measured with ferric reducing antioxidant power,radical scavenging capacity,and oxygen radical absorption capacity assays were first evaluated in the extracts of the shells,skins and kernels of 10 varieties of Pinus *** indicate that these varieties had strong radical scavenging capacities,ferric reducing antioxidant power and oxygen radical absorption ***,flavonoid and procyanidin values ranged from 138.6(#3 kernel)to 518.6(#10 shell)mg GAE/g,from 23.3(#2 kernel)to 70.8(#5 skin)mg RE/g,from 2.5(#2 kernel)to 142.1(#7 skin)mg CE/g,*** scavenging capacity and ferric reducing antioxidant power values were positively correlated to the polyphenol contents which play a major role in antioxidant *** varieties may be divided into two groups by cluster analysis and the variables being *** results will be useful for breeding varieties and guiding their production.

关键词： Cluster analysis Radical scavenging capacity(DPPH) Ferric reducing antioxidant power(FRAP) Oxygen radical absorption capacity(ORAC)