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Journal of Materials Science & Technology 2007年第6期23卷 342-346页

作者： Wen LIU Shuming XING peiwei bao Milan ZHANG Liming XIAO Beijing Jiaotong University Beijing 100044 China

The energy dissipation caused by the viscous force has great effects on the flow property of semi-solid metal during rheological processes such as slurry preparing, delivering and cavity filling. Experimental results in this paper indicate that the viscous friction between semi-solid metal and pipe wall, the collisions among the solid particles, and the liquid flow around particles are the three main types of energy dissipation. On the basis of the hydromechanics, the energy dissipation calculation model is built. It is demonstrated that the micro-structural parameters such as effective solid fraction, particle size and shape, and flow parameters such as the mean velocity, the fluctuant velocity of particles and the relative velocity between the fluid and solid phase, affect the energy dissipation of semi-solid metal.

关键词： Semi-solid metal Energy dissipation Rheology Apparent viscosity Model

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Numerical Simulation of Two Types of Electromagnetic Edge Dam Used in Twin Roll Strip Casting

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Journal of Materials Science & Technology 2005年第4期21卷 526-530页

作者： peiwei bao Peijie LI Hongshuang DI Xianghua LIU Guodong WANG Key Laboratory for Advanced Manufacturing by Materials Processing Technology Department of Mechanical Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China

Two types of electromagnetic edge dams were analyzed by using finite element method in present paper. The magnetic vector potential method and edge element method were used. The distributions of the magnetic field, the eddy current intensity and the magnetic force were obtained from the computing. The differences in these fields were explained according to the two types of electromagnetic dam, and characters of their application in twin roll casting were also discussed.

关键词： Twin roll casting Electromagnetic field Electromagnetic containment Numerical simulation Finite element

Particle motion behavior during gasiication of foam carrier in lost foam-squeeze casting of 20%TiC/ZG270-500 composites

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China Foundry 2013年第6期10卷 367-373页

作者： Bin Shibo Xing Shuming Guo Lijun bao peiwei School of Mechanical ElectronicControl Engineering Beijing Jiaotong University

The particle motion behavior affects the distribution of particles in the metal matrix and finally determines the mechanical properties of the particle reinforced metal-matrix composites. To obtain a uniform distribution of TiC particles and excellent strengthening effect in 20%TiC/ZG270-500 composites fabricated by lost foam-squeeze casting （LFSC）, the particle motion behavior in the gas gap and the conditions of the particles getting into the molten steel were investigated. The results show that the airflow velocity （vl） and TiC particle motion velocity （up） change little with the pouring temperature （Tp）, increase with an increase in metal filling velocity （Vp）, ratios of cross sections of in-gate/orifice （AAAo） and orifice/mould cavity （AolAI）, but the increase trend of up is more intense. The airflow pressure （P1） changes little with Tp and Ao/A1, but increases with the increasing of vp and AJAo. Besides, there is a critical velocity （v ＋｜3YLG cosθ/ppdp｜1/2）for the particles getting into the molten steel. The higher the particle motion velocity, the easier the particles get into the molten steel and the more uniform the distribution of the particles in the steel matrix. When Tp = 1,873 K, vp = 30 mm.s-1, AJAo =10 and Ao/AI = 0.02 in this study, the biggest TiC particle motion velocity （20.59 m.s-~） can be gained, and the steel matrix with the most uniformly distributed TiC particles and fine grains are obtained.

关键词： lost foam-squeeze casting (LFSC) particle motion velocity critical velocity particle distribution

Design of process parameters for direct squeeze casting

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Journal of University of Science and Technology Beijing 2008年第3期15卷 339-343页

作者： Milan Zhang Shuming Xing Liming Xiao peiwei bao Wen Liu Qiao Xin Semisolid Forming Research Center Beijing Jiaotong University Beijing 100044 China Department of Mathematics lli Normal University Yining 835000 China

On the basis of the analysis of solidification interval and temperature distribution of components manufactured by the squeeze casting method, formulas for calculating the solidification interval and compaction pressure were deduced according to the principal request that the compaction pressure should be equal to or greater than the plastic deformation resistance of the forming component when solidification ended. The solidification interval was proven to be associated with many factors, such as weight of the component, specific heat of the alloy, latent heat, pouring temperature, component temperature at the end of solidification and heat-transfer coefficients. The compaction pressure was related to the strain rate, deformation temperature, and dimension of the de- forming component. The solidification interval and compaction pressure calculated by the formulas deduced in this article were adopted in the production of 45 steel bidirectional chapiter valves, and components with excellent oerformance were manufactured.

关键词： squeeze casting solidification time temperature distribution compaction pressure

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比压对液态模锻铍青铜件组织和性能的影响

精密成形工程 2024年第4期16卷 165-171页

作者：邢书明高文静鲍培玮闫光远韩亮杨景华高颖北京交通大学机械与电子控制工程学院北京100044 河北省安全工具产业技术研究院河北沧州062150 河北中泊防爆工具集团有限公司河北沧州062150

目的针对先铸坯再模锻方法工艺流程长、能耗高、成本高的缺点,将液态模锻工艺应用于铍青铜件的成形制造中,以提高零件的成形质量、降低成本和能耗。方法在工业生产条件下,对比研究了主要工艺参数比压对液态模锻铍青铜件试样拉伸性能、... 详细信息

目的针对先铸坯再模锻方法工艺流程长、能耗高、成本高的缺点,将液态模锻工艺应用于铍青铜件的成形制造中,以提高零件的成形质量、降低成本和能耗。方法在工业生产条件下,对比研究了主要工艺参数比压对液态模锻铍青铜件试样拉伸性能、冲击性能、硬度及晶粒特征的影响规律。结果当液锻比压从40 MPa提高至80 MPa时,液锻铍青铜的晶粒尺寸可以细化至65μm以下,抗拉强度提高了150 MPa,伸长率由20%提高至40%,硬度和冲击韧性分别提高了35HBW和20 J/cm^(2)。结论液锻比压是影响铍青铜液锻件组织和性能的关键因素,随着液锻比压的增大,液锻铍青铜件晶粒被显著细化,强度、塑性、硬度和冲击韧性均得到显著提高。

关键词：铍青铜液态模锻比压显微组织力学性能

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Two Dimension Finite Element Simulations on the Electromagnetic Containment in Twin-Roll Strip Casting

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Journal of Materials Science & Technology 2003年第1期19卷 9-12页

作者： peiwei bao, Hongshuang DI, Xiaoming ZHANG, Guodong WANG and Xianghua LIUState Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110004, China Lab. of Rolling and Automat. Northeastern Univ. Shenyang 110004 China

Distribution of magnetic field and electromagnetic force in twin-roll casting of steels was studied by the method of numericalsimulation in this paper. Two-dimension finite element model, which includes the regions of melt, stainless collar, coil andmagnetic core, has been constructed. By solving magnetic vector potential formulations of quasi-static electromagnetic field,distribution of magnetic flux density and magnetic force at different molten height is determined. Calculated results showedthat intensity of the distribution of magnetic flux density increased linearly with the increased coil current; and the magneticforce in the melt increased as a quadratic cure with creased coil current. More attention was given to the distribution of eddycurrent and magnetic force in the melt, the confine effect at different molten height was also discussed.

关键词： Twin roll casting Electromagnetic field Electromagnetic containment Simulation Finite element

3-D Numerical Simulation of the Electromagnetic Dam of Twin Roll Casting using Edge Element Method

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Journal of Materials Science & Technology 2003年第2期19卷 116-119页

作者： peiwei bao, Hongshuang DI, Aiwen QIAN, Xiaoming ZHANG and Guodong WANGState Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110004, China Lab. of Rolling and Automat. Northeastern Univ. Shenyang 110004 China

The 3-dimension numerical simulation study on the electromagnetic dam used in the twin roll caster has been performed by using the edge element method. It was found that the materials and structures of the roll collars have great influence on the distribution of the magnetic flux density, eddy current density and the electromagnetic force in the molten pool. The conductive collars make the magnetic flux density decreased in the molten pool, but it also makes the magnetic force more uniformly, and the force in the low part of the molten pool where needs greater force have increased some what. The conductive collars make the EMD device more effective than the nonconductive collars.

关键词： Simulation Edge element method Electromagnetic confinement Twin roll casting Electromagnetic field

A New Analytical Model for the Flow Stress of Twin-roll Casting Magnesium Sheet at Elevated Temperatures

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Journal of Materials Science & Technology 2010年第5期26卷 461-466页

作者： Zhimin Liu,Shuming Xing ,peiwei bao,Nan Li,Shuqing Yao and Milan Zhang School of Mechanical,Electronic and Control Engineering,Beijing Jiaotong University,Beijing 100044,China School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing 100044 China

To evaluate the flow stress of the twin-roll casting magnesium sheet in high temperature forming processes,a new analytical model was proposed by analyzing stress-strain curves measured under various temperatures and strain *** model can be parameterized to reflect the volume fraction of semi-sold grain and sold grains undergoing *** applying the new model,the result showed that the simulated stress-strain curves fit the experiment data very *** curve fitting can be employed for any magnesium sheet when the deformation conditions are *** evolution indicated that it affected the stress-strain curves *** mechanisms of dynamic recrystallization（DRX） depended on the operating deformation mechanisms,which changed with *** the volume fraction and grain size of DRX changed with the Zener-Hollomon parameter and temperatures.

关键词： Twin-roll casting Semi-sold grains Twinning

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轧辊挤压铸造关键工艺参数的研究

特种铸造及有色合金 2014年第8期34卷 820-823页

作者：杨淼邢书明鲍培伟北京交通大学机械与电子控制工程学院

提出了利用挤压铸造工艺制造轧辊,并根据材料力学和凝固理论导出了轧辊挤压铸造工艺中开始加压时间和保压时间的定量计算模型。同时,结合轧辊挤压铸造工作原理,定义了该零件挤压铸造时的浇注高度,并给出了其计算公式。通过数值模拟软件P... 详细信息

提出了利用挤压铸造工艺制造轧辊,并根据材料力学和凝固理论导出了轧辊挤压铸造工艺中开始加压时间和保压时间的定量计算模型。同时,结合轧辊挤压铸造工作原理,定义了该零件挤压铸造时的浇注高度,并给出了其计算公式。通过数值模拟软件ProCAST对规格为175mm×480mm的轧辊进行模拟及其缩小样的验证试验,结果表明该轧辊在挤压铸造工艺下无缩孔、缩松等缺陷。

关键词：挤压铸造(液态模锻) 轧辊开始加压时间保压时间浇注高度

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钢铁零件挤压铸造的工业化应用

特种铸造及有色合金 2012年第1期32卷 30-33页

作者：邢书明鲍培伟于冬王硕北京交通大学机械与电子控制工程学院

我国钢铁零件挤压铸造目前已经进入针对具体零件推广应用的新时期,主要生产设备和工艺技术正在向专业化方向发展,轮盘盖、叉架座和箱体类钢铁零件的挤压铸造都已获得成功应用。实践证明,该工艺适用性强、成本低、绿色度高,适于生产高品... 详细信息

我国钢铁零件挤压铸造目前已经进入针对具体零件推广应用的新时期,主要生产设备和工艺技术正在向专业化方向发展,轮盘盖、叉架座和箱体类钢铁零件的挤压铸造都已获得成功应用。实践证明,该工艺适用性强、成本低、绿色度高,适于生产高品质要求的中小工件。今后的研究重点是钢铁零件挤压铸造工艺设计准则研究和从热.力.材三方耦合的角度进行专用涂料的系列化研究、模具设计的科学化和模具材料的最优化研究。

关键词：钢铁零件挤压铸造涂料