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Effects of Process Parameters of Semisolid Stirring on Microstructure of Mg–3Sn–1Mn–3SiC(wt%) Strip Processed by Rheo-rolling

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Acta Metallurgica Sinica(English Letters) 2017年第1期30卷 66-72页

作者： zhan-yong zhao Ren-Guo Guan Jian-Hong zhang Zhou-Yang zhao Pei-Kang Bai School of Materials Science and Engineering North University of China School of Materials Science and Engineering Northeastern University

A novel semisolid stirring and rheo-rolling process for preparing Mg-3Sn-1Mn-3SiC （wt%） composite strips was proposed, and the effects of process parameters of semisolid stirring on microstructures of Mg-3Sn-1Mn-3SiC （wt%） composite strips were investigated. The average grain size and roundness decrease, and the distribution of SiC becomes more homogeneous with the decrease in stirring temperature and the increase in the stirring speed. When the stirring time is increased, the distribution of SiC particles tends to be homogeneous, and the average grain diameter and roundness of α- Mg grain decrease. Under the following process parameters： the stirring temperature at 640 ℃, the stirring speed at 1100 rpm, the stirring time at 30 min and the roll speed at 0.2 m/s, Mg-3Sn-1Mn-3SiC （wt%） strip with a cross-sectional size of 4 mm × 160 mm was prepared. The ultimate tensile strength and elongation of Mg-3Sn-1Mn-3SiC （wt%） composite strip reached 226 ± 6 MPa and （7.4 ± 0.2）%, which are obviously improved in comparison with Mg-3Sn-1Mn （wt%）.

关键词： Mg-matrix composite Rheo-rolling Microstructure Property

Microstructure and properties of A2017 alloy strips processed by a novel process by combining semisolid rolling,deep rolling,and heat treatment

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International Journal of Minerals,Metallurgy and Materials 2013年第8期20卷 770-778页

作者： Ren-guo Guan Xiang Wang zhan-yong zhao Wei-wei Wang Fu-rong Cao Chun-ming Liu College of Materials and Metallurgy Northeastern University

A novel short process for producing A2017 alloy strips with notable features of near net shape, saving energy, low cost, and high product performance was developed by combining semisolid rolling, deep rolling, and heat treatment. The microstructure and properties of the A2017 alloy strips were investigated by metallographic microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, tensile testing, and hardness measurement. The cross-sectional microstructure of the A2017 alloy strips is mainly composed of near-spherical primary grains. Many eutectic phases CuA12 formed along primary grain boundaries during semisolid rolling are crushed and broken into small particles. After solution treatment at 495℃ for 2 h the eutectic phases at grain boundaries have almost dissolved into the matrix. When the solution treatment time exceeds 2 h, grain coarsening happens. More and more grain interior phases precipitate with the aging time prolonging to 8 h. The precipitated particles are very small and distribute homogenously, and the tensile strength reaches its peak value. When the aging time is prolonged to 12 h, there is no obvious variation in the amount of precipitated phases, but the size and spacing of precipitated phases increase. The tensile strength of the A2017 alloy strips produced by the present method can reach 362.78 MPa, which is higher than that of the strips in the national standard of China.

关键词： aluminum alloys semisolid rolling heat treatment microstructure mechanical properties

Model for Influences of Magnetic Fields on Intracellular Calcium Oscillations

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Communications in Theoretical Physics 2009年第7期52卷 168-172页

作者： zhanG Yu-Hong zhan yong zhao Tong-Jun CHEN Ya-Fei YUAN Chang-Qing School of Sciences Hebei University of Technology Tianjin 300130 China

Based on the model of the two calcium stores developed by Goldbeter, the influence of external magnetic field on the calcium concentration has been discussed. We believe that the cell membrane is a major site of interaction for extremely-low-frequency （ELF） electromagnetic fields, and the permeability of ions can be changed with the changing electromagnetic fields. It is shown that magnetic field initiates intraeellular calcium oscillation with a threshold in flux density, and that the calcium oscillations do not occur if the density of magnetic field is below the threshold. The results of theoretical calculation are consistent with that of the experiment. The intracellular free calcium concentrations of different cells exposed to the same magnetic fields are different from each other. It is indicated that the different behaviors such as oscillation, rise and invariability of calcium concentration are associated with the sort of cells.

关键词： calcium oscillation magnetic fields calcium concentration

Mathematic model of rolling pressure during a semisolid shearing-rolling process

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International Journal of Minerals,Metallurgy and Materials 2012年第12期19卷 1121-1127页

作者： Ren-guo Guan zhan-yong zhao Chao Lian Qiu-sheng zhang Chun-ming Liu College of Materials and Metallurgy Northeastern UniversityShenyang 110819China

A mathematic model of rolling pressure during a novel semisolid shearing-rolling process was established. The rolling pressure in this process is higher than that in the conventional rolling. The increment of rolling pressure in the backward slip zone is higher than that in the forward slip zone, and the neutral plane moves toward to the roll gap entrance. The maximum and the average rolling pressures increase with the decrease of strip thickness, and the effects of strip thickness on the rolling pressure is more obvious in the forward slip zone than in the backward slip zone. Meanwhile, the neutral plane moves toward the roll gap exit with the decrease of strip thickness. The maximum and average rolling pressures increase with the decrease of strip width, and the strip width affects the pressure more obviously in the backward slip zone than in the forward slip zone. At the same time, the neutral plane moves toward the roll gap entrance with the decrease of strip width. The maximum and average rolling pressures increase with increasing roll radius, and the neutral plane moves toward the roll gap exit.

关键词： semisolid rolling pressure mathematic models strips magnesium alloys

Damage characteristics of fused silica under low-temporal coherence light

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High Power Laser Science and Engineering 2024年第3期12卷 77-83页

作者： Chong Shan Lingbao Kong Fujian Li yong Cui Lailin Ji Quan Zheng Daxing Rao Ruijing He Xiaohui zhao Yuanan zhao zhan Sui Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing School of Information Science and TechnologyFudan UniversityShanghaiChina Shanghai Institute of Laser Plasma China Academy of Engineering PhysicsShanghaiChina Key Laboratory of High Power Laser Materials Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina

The damage characteristics of fused silica were investigated under low-temporal coherence light(LTCL).It was found that the laser-induced damage threshold(LIDT)of fused silica for the LTCL was lower than that of the single longitudinal mode pulse laser,and for the LTCLs,the LIDTs decrease with the increasing of laser bandwidth,which is not consistent with the temporal spike *** is due to the nonlinear self-focusing effect and multi-pulse accumulation *** specific reasons were analyzed based on theoretical simulation and experimental *** research work is helpful and of great significance for the construction of high-power LTCL devices.

关键词： laser-induced damage threshold low-temporal coherence light nonlinear self-focusing effect temporal spike

Kinetic model of vibration screening for granular materials based on biological neural network

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Particuology 2024年第5期88卷 98-106页

作者： zhan zhao Yan zhang Fang Qin Mingzhi Jin School of Agricultural Engineering Jiangsu UniversityZhenjiang212013China Shandong Academy of Agricultural Machinery Sciences Ji'nan250100China

The kinetic model is the theoretical basis for optimizing the structure and operation performance of vibration screening *** this paper,a biological neurodynamic equation and neural connections were established according to the motion and interaction properties of the material under vibration *** material feeding to the screen and the material passing through apertures were considered as excitatory and inhibitory inputs,respectively,and the generated stable neural activity landscape was used to describe the material distribution on the 2D screen *** dynamic process of material vibration screening was simulated using discrete element method(DEM).By comparing the similarity between the material distribution established using biological neural network(BNN)and that obtained using DEM simulation,the optimum coefficients of BNN model under a certain screening parameter were determined,that is,one relationship between the BNN model coefficients and the screening operation parameters was *** screening parameters were randomly selected,and the corresponding relationships were established as a ***,with straw/grain ratio,aperture diameter,inclination angle,vibration strength in normal and tangential directions as inputs,five independent adaptive neuro-fuzzy inference systems(ANFIS)were established to predict the optimum BNN model coefficients,*** training results indicated that ANFIS models had good stability and *** flexibility and adaptability of the proposed BNN method was demonstrated by modeling material distribution under complex feeding conditions such as multiple regions and non-uniform rate.

关键词： Kinetic model Material distribution Vibration screening Biological neural network DEM simulation Adaptive neuro-fuzzy inference systems

Chirality transfer induced circularly polarized luminescence of achiral dye molecules by plasmonic nanohelicoid

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Nano Research 2024年第9期17卷 8408-8414页

作者： Han Gao ChunLian zhan Tianqi zhao Jianzhong Zheng College of Optical and Electronic Technology China Jiliang UniversityHangzhou 310018China School of Environmental Science and Engineering Nanjing Tech UniversityNanjing 211816China

Optical materials with circularly polarized luminescence(CPL)features have attracted a growing interest due to their crucial role in biological sensing,display,spintronics,information storage,and so ***,CPL emissions in hybrid nanoparticle systems,in particular,chirality transfer induced CPL from chiral plasmonic nanoparticles,have rarely been explored due to a lack of effective bottom-up synthesis ***,we creatively take advantage of the newly introduced chiral plasmonic nanoparticles-gold nanohelicoid(GNH)to excite the CPL of achiral Rhodamine 6G(R6G).The fabricated GNH@R6G-SiO_(2)shows obvious CPL signals with|g_(lum)|up to *** with the single GNH,the photoluminescence(PL)dissymmetry factor of the single GNH@R6G-SiO_(2)is similar,but with 25 folds higher PL intensities under different circular *** research not only offers an effective and feasible method to fabricate single-particle level CPL-active materials,but also provides guidelines on how to regulate the CPL of achiral luminophores from chiral plasmonic nanostructures,thereby enlarging the category and quantity of CPL-active materials that can be applied for photonic technologies and visualization biosensing,especially some intracellular chirality related detection.

关键词： circularly polarized luminescence gold nanohelicoids chiral plasmonic

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一种模块式自动化激光诱导击穿光谱测控系统

光电子．激光 2015年第8期26卷 1561-1567页

作者：杨诚詹永照常州信息职业技术学院江苏常州213164 江苏大学计算机科学与通信工程学院江苏镇江212013

为提高激光诱导击穿光谱（LIBS）仪对不同型号部件的兼容性,优化LIBS仪参数和测试流程,研制了一种模块式的自动化LIBS测控系统。实际测试表明,研制的测控系统可以兼容市场上大部分类型的LIBS部件,提升了LIBS仪对不同部件的兼容性及自身... 详细信息

为提高激光诱导击穿光谱（LIBS）仪对不同型号部件的兼容性,优化LIBS仪参数和测试流程,研制了一种模块式的自动化LIBS测控系统。实际测试表明,研制的测控系统可以兼容市场上大部分类型的LIBS部件,提升了LIBS仪对不同部件的兼容性及自身的灵活性,其中光谱仪、激光器等核心部件已测试兼容至少3种不同型号的部件。此外,设计多层迭代式自动化测试流程,提高了LIBS仪参数优化过程的效率。在延时时间的优化测试中,延时时间的优化范围为1.28-18.28μs,步进值分别为1.0、0.5、0.2和0.1μs时,与手动测试平台相比,测试效率分别提升了2.81、3.15、3.72和4.15倍。

关键词：激光器激光诱导击穿光谱(LIBS) 测控系统部件

Bridging microstructure and crystallography with the crack propagation behavior in Ti-6Al-4V alloy fabricated via dual laser beam bilateral synchronous welding

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Journal of Materials Science & Technology 2024年第7期174卷 1-14页

作者： Tingyan Yan Yuan Liu Jianfeng Wang yong Zheng Xiaohong zhan College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China

The microstructure evolution and crack propagation behavior were systematically and thoroughly inves-tigated inα/βTi-6Al-4V alloy obtained under the inhomogeneous heating effect of a coupled dual laser beam via a combination of postmortem electron backscattering diffraction analyses and numerical *** effect of microstructural attributes(grain size,grain boundary,dislocation)on the fracture property and crack propagation behavior was investigated based on thermodynamic and crystallographic analyses,as well as the examinations of dislocation density and the Burgers *** quantifying the degree of variant selection using the degree of variant selection(DVS)equation,it was found that the higher the energy input,the weaker the variant selection,as the secondaryαphase suppresses further dislocation-induced variant selection via autocatalytic nucleation and *** proportion of high an-gle grain boundaries(HAGBs)concentrated around 60°gradually increases with improving cooling rate,mainly due to the change in the tendency of martensite transformation to be *** grain refine-ment was the primary mechanism for the enhancement of Ti-6Al-4V alloy T-joints,while the suppression of crack propagation by HAGBs also played a crucial role in improving strength and *** crack propagation direction frequently changes when the order is approximately parallel to the short axis ofαmartensite grains,forming a zigzag propagation *** above findings should shed light on optimiz-ing dual laser beam bilateral synchronous welding(DLBSW)technology to tailor the microstructure and improve the mechanical properties of Ti-6Al-4V alloy T-joints.

关键词： Ti-6Al-4V alloy Microstructure Grain refinement Crack propagation Dual laser beam bilateral synchronous welding