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Journal of Materials Science & Technology 2022年第13期108卷 54-63页

作者： Bang Xiao Wenpeng Jia huiping tang Jian Wang Lian Zhou State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Porous Metal Materials Northwest Institute for Non-ferrous Metal ResearchXi’an 710016China

WMoTaNbTi RHEAs formed by SEBM with negative defocus distance were *** scanning speeds were applied,an electron beam with scanning speed at 2.5 m/s completely fused the premixed WMoTaNb alloyed powder and pure Ti *** vaporization of Nb and Ti elements happened during the formation of WMoTaNbTi RHEAs,however,the single BCC phase remains *** solid-solute strengthening caused by elemental vaporization,dropping percentage of Nb and Ti solutes in the matrix as well as improved ductilizing effects with decreasing scanning speeds leads to falling microhardness and better local *** of scanning speed at 4.0 m/s,3.5 m/s,3.0 m/s and 2.5 m/s is 578±17 HV,576±12 HV,573±10 HV and 511±2 HV,*** as-deposited WMoTaNbTi RHEA formed at a scanning speed of 2.5 m/s displays ultimate strength of 1312 MPa.

关键词： Refractory high-entropy alloys Selective electron beam melting Solidification cracking Porosity Solid-solution strengthening

Additive manufacturing of Ti-6Al-4V lattice structures with high structural integrity under large compressive deformation

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Journal of Materials Science & Technology 2019年第2期35卷 303-308页

作者： Kun Yang Jian Wang Liang Jia Guangyu Yang huiping tang Yuanyuan Li College of Materials Science and Engineering Jilin University State Key Laboratory of Porous Metal Materials Northwest Institute for Nonferrous Metal Research

Additively manufactured Ti-6 Al-4 V lattice structures have found important niche applications. However, they often show insufficient compressive ductility or insufficient structural integrity. In this study,a batch of 45 octahedral Ti-6 Al-4 V lattice structures was manufactured in three different strut diameters(0.5, 1.0, 1.5 mm) by selective electron beam melting(SEBM). The influence of post-SEBM annealing on the compressive deformation characteristics of the lattice structure was investigated. The as-built Ti-6 Al-4 V lattices fragmented when the compressive strain reached 13%–23% depending on strut *** at 950?C(β transus temperature: 995?C) only slightly improved the compressive ductility of the lattice structures. However, annealing at 1050?C(β-annealing) fundamentally changed the compressive deformation mode of the lattice structures. The resultant compressive stress-strain curve was featured by a long smooth plateau and no facture occurred even after significant densification of the lattice structure had taken place(>50% of compressive strain).

关键词： Selective electron beam melting Ti-6Al-4V Lattice structures Ductility Annealing Beta annealing

Dynamic flow resistivity based model for sound absorption of multi-layer sintered fibrous metals

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Science China(Technological Sciences) 2014年第11期57卷 2096-2105页

作者： MENG Han AO QingBo tang huiping XIN FengXian LU TianJian State Key Laboratory for Mechanical Structure Strength and Vibration School of Aerospace Xi'an Jiaotong University State Key Laboratory of Porous Metal Materials Northwest Institute for Nonferrous Metal Research

The sound absorbing performance of the sintered fibrous metallic materials is investigated by employing a dynamic flow resistivity based model,in which the porous material is modeled as randomly distributed parallel fibers specified by two basic physical parameters:fiber diameter and porosity.A self-consistent Brinkman approach is applied to the calculation of the dynamic resistivity of flow perpendicular to the cylindrical *** on the solved flow resistivity,the sound absorption of single layer fibrous material can be obtained by adopting the available empirical ***,the recursion formulas of surface impedance are applied to the calculation of the sound absorption coefficient of multi-layer fibrous *** measurements are conducted to validate the proposed model,with good agreement achieved between model predictions and tested *** calculations with the proposed model are subsequently performed to quantify the influences of fiber diameter,porosity and backed air gap on sound absorption of uniform(single-layer)fibrous *** show that the sound absorption increases with porosity at higher frequencies but decreases with porosity at lower *** sound absorption also decreases with fiber diameter at higher frequencies but increases at lower *** sound absorption resonance is shifted to lower frequencies with air *** multi-layer fibrous materials,gradient distributions of both fiber diameter and porosity are introduced and their effects on sound absorption are *** is found that increasing the porosity and fiber diameter variation improves sound absorption in the low frequency *** model provides the possibility to tailor the sound absorption capability of the sintered fibrous materials by optimizing the gradient distributions of key physical parameters.

关键词： sound absorption sintered fibrous material dynamic flow resistivity

Improvement of Ductility of Powder Metallurgy Titanium Alloys by Addition of Rare Earth Element

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Journal of Materials Science & Technology 2006年第4期22卷 465-469页

作者： Yong LIU Lifang CHEN Weifeng WEI huiping tang Bin LIU Baiyun HUANG State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China Northwest Institute of Nonferrous Metals Research Xi＇an 710016 China

Ti-4.5Al-6.0Mo-1.5Fe, Ti-6Al-1Mo-1Fe and Ti-6Al-4V alloys were prepared by blended elemental powder metallurgy （PM） process, and the effects of Nd on the microstructures and mechanical properties were investigated by scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and X-ray diffraction （XRD）. It was found out that the addition of Nd increased the density of sintered titanium alloys slightly by a maximum increment of 1% because small amount of liquid phase occurred during sintering. The addition of Nd shows little effect on the improvement of tensile strength, while the elongation is significantly improved. For example, the elongation of ***-6.0Mo-1.5Fe can be increased from 1% without addition of Nd to 13% at a Nd content of 1.2 wt pct.

关键词： Powder metallurgy titanium alloy Mechanical properties Microstructure Rare earth element

Superplastic Behavior of Alumina Composites Mediated by Carbon Nanotubes

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Nano-Micro Letters 2013年第3期5卷 174-181页

作者： Xiaobing Zhou Lei Li Lu Shen Jie Zhou Junwei Zhang Amiya K. Mukherjee Changshu Xiang huiping tang Qing Huang Division of Functional Materials and Nanodevices Ningbo Institute of Materials Technology and Engineering (NIMTE) Chinese Academy of Sciences (CAS) Department of Chemical Engineering & Materials Science University of California State Key Laboratory of Porous Metal Materials Northwest Institute for Nonferrous Metal Research

The high temperature creep behavior of carbon nanotube(CNT)/alumina was mediated by the surface chemical functionalization used for synthesis of composite powders. Non-covalent functionalized carbon nanotubes make composites ductile, but covalent approach leads composites that are creep-resistant. Oxygen vacancy mechanism is proposed to account for this mediation effect in this communication.

关键词： Carbon nanotubes Alumina Microstructure Superplasticity

粉末床电子束3D打印Ti-6Al-4V合金的工程应用技术研究进展

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中国材料进展 2020年第7期39卷 551-558页

作者：汤慧萍西北有色金属研究院金属多孔材料国家重点实验室陕西西安710016

电子束选区熔化(selective electron beam melting,SEBM)是20世纪90年代初期发展起来的一类金属3D打印工艺,具有能量利用率高、成形效率高和成形应力低的突出优点,并且是在真空环境中成形,特别适用于高熔点、高活性、脆性金属材料复杂... 详细信息

电子束选区熔化(selective electron beam melting,SEBM)是20世纪90年代初期发展起来的一类金属3D打印工艺,具有能量利用率高、成形效率高和成形应力低的突出优点,并且是在真空环境中成形,特别适用于高熔点、高活性、脆性金属材料复杂构件的高质量制造。由于其是一种粉末床熔融型3D打印工艺,通常也称之为粉末床电子束3D打印技术。从粉末床电子束3D打印的粉末原料、组织与性能、复杂构件的成形能力和工程应用等方面,介绍了作者团队10多年来在粉末床电子束3D打印稀有金属材料方面的工作积累,重点介绍了粉末床电子束3D打印Ti-6Al-4V合金的研究进展,最后结合3D打印技术整体发展趋势对粉末床电子束3D打印技术的发展前景和重点发展方向进行了展望。

关键词：电子束选区熔化成形能力 Ti-6Al-4V 组织与性能

Impact factors of fractal analysis of porous structure

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Science China(Technological Sciences) 2010年第2期53卷 348-351页

作者： tang huiping, ZHU JiLei, XI ZhengPing, DI XiaoBo, WANG JianYong & AO QingBo State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China 1. State Key Laboratory of Porous Metal Materials Northwest Institute for Nonferrous Metal Research Xi’an 710016 China

Characterization of pore structure is one of the key problems for fabrication and application research on porous materials. But, complexity of pore structure makes it difficult to characterize pore structure by Euclidean geometry and traditional experimental methods. Fractal theory has been proved effective to characterize the complex pore structure. The box dimension method based on fractal theory was applied to characterizing the pore structure of fiber porous materials by analyzing the electronic scanning microscope (SEM) images of the porous materials in this paper. The influences of image resolution, threshold value, and image magnification on fractal analysis were investigated. The results indicate that such factors greatly affect fractal analysis process and results. The appropriate magnification threshold and fractal analysis are necessary for fractal analysis.

关键词： porous materials fractal dimension porous structure

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等离子旋转电极制粉技术研究进展

粉末冶金技术 2023年第1期41卷 2-11,54页

作者：汤慧萍浙大城市学院先进材料增材制造创新研究中心杭州310015

等离子旋转电极制粉技术是当前生产高品质球形金属粉末的重要技术之一,通过电极高速旋转产生的离心力将液膜甩出形成液滴,在惰性气氛中雾化凝固成球形粉末。该技术制备的粉末已成为增材制造、热等静压、表面喷涂等制造技术的重要原料。... 详细信息

等离子旋转电极制粉技术是当前生产高品质球形金属粉末的重要技术之一,通过电极高速旋转产生的离心力将液膜甩出形成液滴,在惰性气氛中雾化凝固成球形粉末。该技术制备的粉末已成为增材制造、热等静压、表面喷涂等制造技术的重要原料。本文回顾了国内外等离子旋转电极制粉技术的发展历史,综述了近年来国内外发展现状,特别是总结了等离子旋转电极装备和技术在中国的发展情况,指出了该技术尚需研究的科学技术问题和发展方向。

关键词：等离子旋转电极金属粉末装备增材制造粉末冶金

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微波烧结316L不锈钢纤维毡研究（英文）

稀有金属材料与工程 2017年第9期46卷 2379-2383页

作者：马军汤慧萍李爱君西北有色金属研究院金属多孔材料国家重点实验室陕西西安710016

烧结不锈钢纤维多孔材料是一种结构功能一体化材料,在冲击能量吸收和过滤分离等领域有广泛应用。利用微波加热法制备了316L不锈钢纤维多孔材料,利用μ-CT,SEM等研究了微波烧结工艺对材料微观结构和力学性能的影响。结果表明微波烧结工... 详细信息

烧结不锈钢纤维多孔材料是一种结构功能一体化材料,在冲击能量吸收和过滤分离等领域有广泛应用。利用微波加热法制备了316L不锈钢纤维多孔材料,利用μ-CT,SEM等研究了微波烧结工艺对材料微观结构和力学性能的影响。结果表明微波烧结工艺明显降低了材料的烧结温度,缩短了烧结时间,由此抑制了纤维杆上晶粒的生长,材料的力学性能也得到了提升。微波电磁场在金属纤维间引发的微电弧可起到加快烧结进程的作用。

关键词：微波烧结 316L不锈钢纤维多孔材料拉伸性能晶粒尺寸

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粉末性能对电子束选区熔化快速成形的影响

稀有金属材料与工程 2007年第A03期36卷 574-577页

作者：杨鑫汤慧萍葛渊陕西科技大学材料科学与工程学院陕西西安710021 西北有色金属研究院金属多孔材料与技术国家重点实验室陕西西安710016

在电子束选区熔化金属粉末技术中,为了避免电子束对金属粉末的作用力破坏金属粉末的堆积状态,建立了金属粉末受力模型,并对其进行受力分析和计算。理论分析和实验证明:当球形和非球形粉末以3:2的比例混合时,可以得到很好的成型效果。

关键词：电子束选区熔化钛合金粉末飞散