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整体式副车架液态模锻及其性能

常州大学学报（自然科学版） 2024年第1期36卷 1-8页

作者：邢书明石洪伟江艳星饶宇北京交通大学机械与电子控制工程学院北京100044 广州和德轻量化成型技术有限公司广东广州210098

液态模锻是铝合金件高性能成型的先进工艺,文章将液态模锻技术用于整体式副车架成型,着重研究液锻工艺方案和液锻副车架性能的均匀性。模拟研究表明,单浇道液锻比设有辅助浇道的液锻汇流位置少、表面质量高、工艺出品率高。试生产发现,... 详细信息

液态模锻是铝合金件高性能成型的先进工艺,文章将液态模锻技术用于整体式副车架成型,着重研究液锻工艺方案和液锻副车架性能的均匀性。模拟研究表明,单浇道液锻比设有辅助浇道的液锻汇流位置少、表面质量高、工艺出品率高。试生产发现,利用广州和德轻量化成型技术有限公司设计制造的HVSC2500T卧式液态模锻机进行A356.2铝合金副车架的单浇道液锻,能够获得完整无缺的副车架,本体取样拉伸强度可达320 MPa,延伸率达11.12%。但是,在远离浇道和存在汇流的位置普遍存在夹渣缺陷,副车架强度和塑性都较低。

关键词：副车架液态模锻力学性能缺陷

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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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复杂内腔铝合金件液态模锻试验研究

精密成形工程 2024年第7期16卷 224-232页

作者：石洪伟陈烨煜杨卫谢德强陈楚明杨家洲邢书明广州和德轻量化成形技术有限公司广州511300 北京交通大学机械与电子控制工程学院北京100044

目的为拓宽液态模锻技术的应用范围,实现具有复杂内腔结构件的高性能短流程成形制造,开展了使用砂芯的液态模锻技术试验研究。方法以具有复杂内腔的新能源汽车铝合金空气弹簧顶座为对象,利用广州和德装备制造公司生产的卧式液态模锻机,... 详细信息

目的为拓宽液态模锻技术的应用范围,实现具有复杂内腔结构件的高性能短流程成形制造,开展了使用砂芯的液态模锻技术试验研究。方法以具有复杂内腔的新能源汽车铝合金空气弹簧顶座为对象,利用广州和德装备制造公司生产的卧式液态模锻机,对比研究不同砂芯、涂料及液锻加压制度对黏砂缺陷的影响作用。结果普通砂芯在液锻中容易被压溃或产生黏砂缺陷;在苏铸砂芯的基础上自行配制HDSC01液锻砂芯,配合HDCoating03专用涂料,采用阶梯加压方法进行液态模锻,所得液锻件内表面光洁无黏砂、尺寸精确。结论液态模锻可以使用砂芯进行复杂内腔结构件的高性能精密成形,但工艺控制不当,容易出现黏砂缺陷。阶梯加压、使用专用砂芯和专用涂料是防止黏砂的有效途径。

关键词：液态模锻加压制度砂芯涂料黏砂

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Evaluation of the mold-filling ability of alloy melt in squeeze casting

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Journal of University of Science and Technology Beijing 2006年第1期13卷 60-66页

作者： Haiying Zhang shuming xing Qinghua Zhang Jianbo Tan Wen Liu Semisolid Forming Research Center Beijing Jiaotong University Beijing 100044 China Shijiazhuang Locomotive Depot Shijiazhuang 050000 China Department of Material and Engineering Hebei University of Science and Technology Shijiazhuang 050018 China

The mold-filling ability of alloy mclt in squceze casting process was evaluated by means of the maximum length of Archimedes spiral line. A theoretical evaluating model to predict the maximum filling length was built based on the flowing theory of the incompressible viscous fluid. It was proved by experiments and calculations that the mold-tilling pressure and velocity are prominent influencing factors on the mold-filling ability of alloy melt. The mold-filling ability increases with the increase of the mold-filling pressure and the decrease of the proper mold-filling velocity. Moreover, the pouring temperature relatively has less effect on the mold-filling ability under the experimental conditions. The maximum deviation of theoretical calculating values with experimental results is less than 15%. The model can quantitatively estimate the effect of every factor on the mold-filling ability.

关键词： squeeze casting process parameters mold-filling ability theoretical calculation experimental evaluation

Energy Dissipation and Apparent Viscosity of Semi-solid Metal during Rheological Processes PartⅠ: Energy Dissipation

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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

This study investigated the rheological properties of semi-solid metal. An analytical model of apparent viscosity was built up based on analysis of energy dissipation during rheological processes such as slurry preparing, delivering and model filling. The rheological properties of SSM (semi-solid metal) slurry was described by an analytical model in terms of microstructural parameters, which consist of effective solid fraction, particle size and shape, and flow parameters such as mean velocity, fluctuant velocity and relative velocity between liquid and solid phase. The model was verified in the experiment of A356 alloys with a coaxial double-bucket rheometer. And the maximum relative error between the theoretical value and measured one is less than 10%. The results of experiment and theoretical calculation also indicate that the microstructural parameters and flow parameters are two major factors that affect the apparent viscosity of semi-solid alloys, and fluctuant velocity and relative velocity between liquid and solid phase are the key factors to distinguish between steady and transient rheological properties.

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

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(v1) 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(AP/A0) and orifice/mould cavity(A0/A1), but the increase trend of u P is more intense. The airflow pressure(P1) changes little with TP and A0/A1, but increases with the increasing of vP and AP/A0. Besides, there is a critical velocity(+|3yLGcosθ/ρpdp|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, AP/A0 =10 and A0/A1 = 0.02 in this study, the biggest TiC particle motion velocity(20.59 m·s-1) 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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学科交叉视角下的特种铸造技术及其融合发展

特种铸造及有色合金 2022年第1期42卷 7-13页

作者：邢书明邢若宇北京交通大学机械与电子控制工程学院北京100044 北京科技大学分析检验中心

近年来,各种特种铸造技术互相交叉融合,均取得了巨大发展。重力铸造技术不断引入非重力因素,向加压铸造方向发展;压铸技术在保持其生产薄壁复杂件方面优势的同时,向低速和可热处理方向发展;低压和差压铸造技术向更高压方向发展;半固态... 详细信息

近年来,各种特种铸造技术互相交叉融合,均取得了巨大发展。重力铸造技术不断引入非重力因素,向加压铸造方向发展;压铸技术在保持其生产薄壁复杂件方面优势的同时,向低速和可热处理方向发展;低压和差压铸造技术向更高压方向发展;半固态铸造技术则开始淡化其"半固态"特征,向液态成形和固态成形方向融合发展。这种交叉与融合发展的物理本质是流变充型、流变凝固和流变补缩。

关键词：学科交叉低压铸造半固态铸造挤压铸造

Enhancing the Performance of Perovskite Light-Emitting Diodes via Synergistic Effect of Defect Passivation and Dielectric Screening

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Nano-Micro Letters 2024年第10期16卷 244-256页

作者： Xuanchi Yu Jia Guo Yulin Mao Chengwei Shan Fengshou Tian Bingheng Meng Zhaojin Wang Tianqi Zhang Aung Ko Ko Kyaw shuming Chen Xiaowei Sun Kai Wang Rui Chen Guichuan xing Institute of Applied Physics and Materials Engineering University of MacaoAvenida da UniversidadeTaipaMacao 999078People's Republic of China Department of Electrical and Electronic Engineering Southern University of Science and TechnologyShenzhen 518055People's Republic of China

Metal halide perovskites,particularly the quasi-two-dimensional perovskite subclass,have exhibited considerable potential for next-generation electroluminescent materials for lighting and ***,the presence of defects within these perovskites has a substantial influence on the emission efficiency and durability of the *** this study,we revealed a synergistic passivation mechanism on perovskite films by using a dual-functional compound of potassium *** dual functional potassium bromide on the one hand can passivate the defects of halide vacancies with bromine anions and,on the other hand,can screen the charged defects at the grain boundaries with potassium *** approach effectively reduces the probability of carriers quenching resulting from charged defects capture and consequently enhances the radiative recombination efficiency of perovskite thin films,leading to a significant enhancement of photoluminescence quantum yield to near-unity values(95%).Meanwhile,the potassium bromide treatment promoted the growth of homogeneous and smooth film,facilitating the charge carrier injection in the ***,the perovskite light-emitting diodes based on this strategy achieve a maximum external quantum efficiency of~21%and maximum luminance of~60,000 cd m^(-2).This work provides a deeper insight into the passivation mechanism of ionic compound additives in perovskite with the solution method.

关键词： Synergistic passivation strategy Defects passivation Dielectric screening Perovskite light-emitting diodes