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International Journal of Minerals,Metallurgy and materials 2022年第7期29卷 1310-1316页

作者： Tongtong Zhang Wenbo Yu chaosheng ma Yuqi Zhou Shoumei Xiong Center of materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China School of materials Science and Engineering Tsinghua UniversityBeijing 100084China

To clarify the relationship between externally solidified crystals(ESCs)and other defects,e.g.,defect bands and pores,two dimensional(2D)and three dimensional(3D)characterization methods were adopted to analyze castings produced using a modified ingate system equipped with and without an ESC *** reduction of ESCs strongly reduced defect band width and shrinkage pore *** reducing the quantity and size of ESCs,net-shrinkage pores were transformed into isolated island-shrinkage *** determined via statistical analysis that the mechanical properties of high pressure die castings were strongly related to the size and fraction of the ESCs rather than porosity *** reduction of ESCs also caused tensile transgranular fracture modes to transform into intergranular fracture ***,casting pressurization strongly reduced pore morphology,volume,and size.

关键词： high-pressure die casting externally solidified crystals porosity 3D reconstruction runner design

The effect of slow shot speed and casting pressure on the 3D microstructure of high pressure die casting AE44 magnesium alloy

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Journal of magnesium and Alloys 2023年第2期11卷 753-761页

作者： chaosheng ma Wenbo YU Tongtong Zhang Zihua Zhang Yihu ma Shoumei Xiong Center of materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Research Center of Rail Vehicles Safety Monitoring and Health management Beijing Jiaotong UniversityBeijing 100044China School of materials Science and Engineering Tsinghua UniversityBeijing 100084China

3D reconstruction and 2D observation were conducted to characterize the microstructure of the castings produced through high pressure die casting with different *** results indicate that shrinkage pores generally co-existed with externally solidiﬁed crystals(ESCs).In specimen produced without fast slow shot speed,big net-shrinkage pores accompanied with ESCs were found in the center of the *** the casting pressurization was introduced,the shrinkage pores gathered to the specimen center and became much less due to the optimization of melt *** more porosity was found near the gate rather than in the middle of the rod bar,especially gas ***ﬁlling process simulation reveals that the middle position of the bars wasﬁrstlyﬁlled and followed by the near gate position accompanied with one intense turbulentﬂow.

关键词： HPDC parameters Externally solidiﬁed crystals(ESCs) Porosity 3D reconstruction.

Study of Mg-Al-Ca magnesium alloy ameliorated with designed Al8Mr4Gd phase

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Journal of magnesium and Alloys 2020年第4期8卷 1084-1089页

作者： chaosheng ma Wenbo Yu Xufeng Pi Antoine Guitton School of Mechanical and Electronic Control Engineering Beijing JiaoTong UniversityBeijingChina Universite de Lorraine-CNRS-Arts et Metiers ParisTech-LEM3 F-57000 MetzFrance Laboratory of Excellence on Design of Alloy Metals for low-niAss Structures(DAmaS) Universite de LorraineF-57073 MetzFrance

To investigate the effect of AlsMn4Gd phase on microstructural and mechanical properties of Mg-Al-Ca magnesium alloy,two Mg-2.5AbCa and Mg-2.5Al2Ca-0.1 Al8Mn4Gd alloys were designed and compared in this *** results show that a small amount of Gd can significantly refine a-Mg grains and change the morphology of AUCa ***,the formed Al8Mn4Gd phase could serve as a heterogeneous nucleation site for the a-Mg grains and AbCa ***,the introduction of Gd not only optimized the mechanical properties of Mg-Al-Ca alloy,but also facilitated the thermal deformation(such as hot rolling).

关键词： Mg-Al-Ca alloy AlgNlruGd phase Microstructure and mechanical properties Hot rolling.

A review of novel ternary nano-layered maX phases reinforced AZ91D magnesium composite

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Journal of magnesium and Alloys 2022年第6期10卷 1457-1475页

作者： Wantong Chen Wenbo Yu chaosheng ma Guozheng ma Laiqi Zhang Haidou Wang Center of materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China State Key Laboratory for Advanced Metals and materials University of Science and Technology Beijing100083China

In recent decades, the demand for lightweight and high specific strength materials brings about the development of magnesium matrix composites. Different from some traditional binary ceramic particles, such as SiC, Al_(2)O_(3), the novel ternary nano-layered M_(n+1)AX_(n)(maX)phase carbide or nitride ceramics exhibit metal-like properties and self-lubricate capacity(where “M” is an early transition metal, “A” belongs to the group A element, “X” is C or/and N, and n = 1–3). Ti_(2)AlC, as the representative of the maX phase, was interestingly introduced into the magnesium matrix. Layered Ti_(2)AlC maX phased reinforced AZ91D magnesium composites manufactured through the stir casting exhibit sufficient deformation capacity due to unique deformation behaviors of maX, namely delamination and the formation of kinking band. Further,the Ti_(2)AlC-AZ91D composites exhibit a distinctive characteristic in strengthening mechanism, damping mechanism and tribological capacity due to the other special properties of maX phase, such as self-lubricated property. Accordingly, to give a comprehensive understanding, we overviewed the fabrication process, microstructural characterization, mechanical properties, damping property and tribological capacity on these composites. In order to understand the A-site effect in maX phase on the microstructure, we introduced another representative Ti_(3)SiC_(2)maX phase to explain the interfacial evolution. In addition, due to the high aspect ratio of maX, maX particles could be orientationally regulated in Mg matrix by plastic deformation such as hot extrusion. Herein, we discussed the anisotropic mechanical and physical properties of the textured composites produced by hot extrusion. Moreover, the potential applications and future development trends of maX phases reinforced magnesium matrix composites were also given and prospected.

关键词： Ternary maX phases magnesium composite Damping Mechanical properties Anisotropic Tribological capacity

The research on the high strength and anti-arc ablation coatings applied in steel conductive rail

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High-Speed Railway 2023年第3期1卷 179-184页

作者： Yihu ma Wenbo Yu chaosheng ma Guozheng ma Center of materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China

In order to enhance the ablation-resistant performance of stainless-steel conductive rails,Mo coating,410 stainless steel coating and 15 wt%Cr_(2)AlIC particles reinforced 410 stainless steel composite coating were prepared and *** from the weak interfacial strength caused by the dissimilar metals between Mo and steel rails,410 stainless steel coating has better interfacial contact with steel *** introduction of Cr_(2)AlC into 410 stainless steels further strengthened the mechanical properties of coating by alloy strengthening effect and particle strengthening effect,as the decomposition of Cr_(2)AlC into nano CrC particles is accompanied with the diffusion of Al atoms into 410 stainless *** was found that the composite coating can still resist arc erosion at 150 A current,as a dense oxide film formed during the ablation process and the decomposition of Cr_(2)AlC contributed to the heat absorption.

关键词： Conductive stainless-steel rails Arc-ablation maX phase Coating

Effects of plasma spraying process on microstructure and mechanical properties of Cr_(2)AlC/410 composite coatings

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High-Speed Railway 2024年第2期2卷 110-115页

作者： Yihu ma chaosheng ma Guozheng ma Wenbo Yu Center of materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China

To investigate the influences of Cr_(2)AlC mass fraction and supersonic plasma spraying process on the microstructure and mechanical properties of Cr_(2)AlC reinforced 410 stainless steel composite coatings,the coatings containing different mass fractions of Cr_(2)AlC were prepared and *** composite coating exhibited low porosity and high adhesion *** addition of Cr_(2)AlC significantly enhanced the hardness of the composite coatings through particle ***,when the mass fraction of Cr_(2)AlC was 20%,the aggregation of Cr_(2)AlC resulted in a strong decrease in the coating preparation efficiency,as well as a decline in adhesion *** the supersonic plasma spraying process,the Ar flow rate mainly influenced the flight velocity of the particles,while the H_(2) flow rate and the current mainly affected the temperature of the plasma ***,all of them influenced the melting degree of particles and the quality of the *** lowest porosity and the highest hardness and adhesion strength could be obtained when the Ar flow rate is 125 L/min,the H_(2) flow rate is 25 L/min,and the current is 385 A.

关键词： maX phase Plasma spray Parameter Coating

Fabrication and performance of 3D co-continuous magnesium composites reinforced with Ti_(2)AlN_(x) maX phase

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International Journal of Minerals,Metallurgy and materials 2022年第7期29卷 1406-1412页

作者： Wantong Chen Wenbo Yu Pengcheng Zhang Xufeng Pi chaosheng ma Guozheng ma Lin Zhang Center of materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China China Academy of machinery Science and Technology Group Co. Ltd.Beijing 100044China

magnesium composites reinforced by N-deficient Ti_(2)AlN maX phase were first fabricated by non-pressure infiltration of Mg into three-dimensional(3D)co-continuous porous Ti_(2)AlN_(x)(x=0.9,1.0)*** relationship between their mechanical properties and micro-structure is discussed with the assessment of 2D and 3D characterization.X-ray diffraction(XRD)and scanning electron microscopy detected no *** 3D reconstruction shows that the uniformly distributed pores in Ti_(2)AlN_(x) preforms are interconnected,which act as infiltra-tion tunnels for the melt *** compressive yield strength and microhardness of Ti_(2)AlN_(0.9)/Mg are 353 MPa and 1.12 GPa,respectively,which are 8.55%and 6.67%lower than those of Ti_(2)AlN/Mg,*** typical delamination and kink band occurred in Ti_(2)AlN_(x) under compressive and Vickers hardness(V_(H))*** to the continuous skeleton structure and strong interfacial bonding strength,the crack ini-tiated in Ti_(2)AlN_(x) was blocked by the plastic Mg *** suggests the possibility of regulating the mechanical performance of Ti_(2)AlN/Mg composites by controlling the N vacancy and the hierarchical structure of Ti_(2)AlN skeleton.

关键词： Ti_(2)AlN magnesium matrix composites co-continuous structure Nvacancy

多传感约束下三维运动图像连带动作高质量仿真

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传感技术学报 2024年第7期37卷 1210-1215页

作者：杨伟华高杰马朝圣江西农业大学南昌商学院公共基础部江西共青城332020 江西财经大学信息学院江西南昌330000

因非刚体三维运动图像在成像过程中,传感器区域的随机性对动作限制大、操作复杂,导致动作虚拟精度较低、图像质量差。为此,提出了多传感约束下三维运动图像连带动作高质量仿真。根据多传感器受重力加速度以及地磁场的作用,求解传感器从... 详细信息

因非刚体三维运动图像在成像过程中,传感器区域的随机性对动作限制大、操作复杂,导致动作虚拟精度较低、图像质量差。为此,提出了多传感约束下三维运动图像连带动作高质量仿真。根据多传感器受重力加速度以及地磁场的作用,求解传感器从原始状态到运动当前状态的角度变化。根据变化数值对图像进行去噪,提取连带动作特征。在Vicon系统中计算连带动作空间位置,捕捉连带动作变换轨迹,将运动轨迹结果输入PAR系统,完成连带动作虚拟成像。仿真结果表明:该方法图像去噪效果较好,传感器响应时间始终低于0.52 s,传感器响应速度较快,连带动作轨迹误差始终低于0.045,动作虚拟仿真精度较高,能够有效提高三维运动图像质量。

关键词：多传感器连带动作高质量仿真 Vicon系统三维运动图像动作虚拟图像去噪

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不同压铸工艺对AE44镁合金的影响

特种铸造及有色合金 2024年第5期44卷 647-655页

作者：李俊杰马超胜张通通于文波熊守美北京交通大学机械与电子控制工程学院北京100091 清华大学材料学院北京100084

为了解AE44镁合金高压压铸件的工艺-组织-力学性能之间的关系,对不同工艺参数下生产的高压压铸件进行了三维重构和二维表征。微观结构表征表明,收缩孔的形成与压室预结晶(ESCs)密切相关,主要受压室内低慢射速度和快慢射速度控制。铸造... 详细信息

为了解AE44镁合金高压压铸件的工艺-组织-力学性能之间的关系,对不同工艺参数下生产的高压压铸件进行了三维重构和二维表征。微观结构表征表明,收缩孔的形成与压室预结晶(ESCs)密切相关,主要受压室内低慢射速度和快慢射速度控制。铸造压力可以通过提高液态金属的供料能力,显著降低心部的孔隙率。充填过程模拟表明,棒状试样中心位置先充填,其后是近浇口位置,并伴有一次强烈的紊流。拉伸试验表明,撕裂脊主要由ESCs的滑移带演化而来。ESCs的数量和分布决定了铸件的断裂行为。

关键词： AE44镁合金高压压铸三维重构 ESCs 断裂行为

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大型集装箱船节能导轮设计研究

中国造船 2017年第1期58卷 1-9页

作者：翟树成马艳郑巢生中国船舶科学研究中心江苏省绿色船舶技术重点实验室无锡214082

采用CFD方法开展了大型集装箱船前置预旋导轮参数优选工作。首先参考节能装置母型设计了大型集装箱船的节能导轮参数,并进行了初步建模和水动力评估。随后开展了节能导轮的优选工作,主要针对导叶攻角、导管长度和扩展角三个参数进行了... 详细信息

采用CFD方法开展了大型集装箱船前置预旋导轮参数优选工作。首先参考节能装置母型设计了大型集装箱船的节能导轮参数,并进行了初步建模和水动力评估。随后开展了节能导轮的优选工作,主要针对导叶攻角、导管长度和扩展角三个参数进行了方案优选,对最终优选方案进行了评估,模型节能效果约为3%,并且预报实船节能效果约为4%,节能效果较好。通过流场分析可知,安装节能装置后,降低了螺旋桨引起的尾流旋转能量损失。项目研究可为大型集装箱船节能导轮设计参数选取提供参考。

关键词： CFD 节能导轮参数研究节能