期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
气体雾化过程中涉及颗粒形貌和空心颗粒形成的金属液滴变形和破碎数值模拟
1
作者 汪鹏 黎兴刚 +5 位作者 周香林 陈志培 王淼辉 甘萍 任晓娜 余志勇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第7期2074-2094,共21页
采用考虑液滴冷却和凝固的流体体积(VOF)方法模拟金属液滴在气体雾化过程中的变形和破碎。建立典型粉末形貌和液滴破碎行为之间的相关性,以指导球形粉末颗粒的制备。结果显示,当增加液滴的气动力与黏性力的比值时,球形颗粒的形成得到加... 采用考虑液滴冷却和凝固的流体体积(VOF)方法模拟金属液滴在气体雾化过程中的变形和破碎。建立典型粉末形貌和液滴破碎行为之间的相关性,以指导球形粉末颗粒的制备。结果显示,当增加液滴的气动力与黏性力的比值时,球形颗粒的形成得到加强;然而,当减小这个比值时,预期的液滴破碎模型将被改变或仅仅只发生液滴的变形。从空心颗粒的形成和演变过程的数值模拟中观察到几种典型的情况,例如,开放的空心液膜的形成、液膜封闭、气泡的离心和气泡的脱离。通过提高气体速度或液滴温度,实现较高的非平衡拉普拉斯压力或较低的粘性力,促使气泡从液滴内部分离。 展开更多
关键词 液滴破碎 空心颗粒 颗粒形貌 黏性力 金属粉末 气体雾化
下载PDF
Semi-solid processing of aluminum and magnesium alloys:Status,opportunity,and challenge in China 被引量:9
2
作者 Gan li Wen-ying QU +8 位作者 Min LUO Le CHENG Chuan GUO xing-gang li Zhen XU Xiao-gang HU Da-quan li Hong-xing LU Qiang ZHU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第11期3255-3280,共26页
Owing to its low cost,short process and low energy consumption,semi-solid processing(SSP)of aluminum(Al)and magnesium(Mg)alloys has been considered as a competitive approach to fabricate complicated components with ex... Owing to its low cost,short process and low energy consumption,semi-solid processing(SSP)of aluminum(Al)and magnesium(Mg)alloys has been considered as a competitive approach to fabricate complicated components with excellent performance.Over the past decade,significant progress has been achieved in deeply understanding the SSP process,the microstructure and performance of the fabricated components in China.This paper starts with a retrospective overview of some common slurry preparation methods,followed by presenting the performance and the underlying mechanisms of SSP fabricated alloys.Then,the mainstream opinions on the microstructure evolution and rheological flow behavior of semi-solid slurry are discussed.Subsequently,the general situation and some recent examples of industrial applications of SSP are presented.Finally,special attention is paid to the unresolved issues and the future directions in SSP of Al and Mg alloys in China. 展开更多
关键词 semi-solid processing aluminum alloys magnesium alloys slurry preparation numerical modeling performance industrial applications
下载PDF
Numerical investigation on flow process of liquid metals in melt delivery nozzle during gas atomization process for fine metal powder production 被引量:6
3
作者 Chang liU Xin li +3 位作者 Shi SHU Yu-he HUANG xing-gang li Qiang ZHU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第10期3192-3204,共13页
Based on volume of fluid(VoF)interface capturing method and shear-stress transport(SST)k-ω turbulence model,numerical simulation was performed to reveal the flow mechanism of metal melts in melt delivery nozzle(MDN)d... Based on volume of fluid(VoF)interface capturing method and shear-stress transport(SST)k-ω turbulence model,numerical simulation was performed to reveal the flow mechanism of metal melts in melt delivery nozzle(MDN)during gas atomization(GA)process.The experimental validation indicated that the numerical models could give a reasonable prediction on the melt flow process in the MDN.With the decrease of the MDN inner-diameter,the melt flow resistance increased for both molten aluminum and iron,especially achieving an order of 10^(2) kPa in the case of the MDN inner-diameter≤1 mm.Based on the conventional GA process,the positive pressure was imposed on the viscous aluminum alloy melt to overcome its flow resistance in the MDN,thus producing powders under different MDN inner-diameters.When the MDN inner-diameter was reduced from 4 to 2 mm,the yield of fine powder(<150μm)soared from 54.7%to 94.2%.The surface quality of powders has also been improved when using a smaller inner-diameter MDN. 展开更多
关键词 gas atomization melt delivery nozzle liquid metal flow resistance metal powder
下载PDF
Characterization of cooling rate and microstructure of Cu Sn melt droplet in drop on demand process 被引量:1
4
作者 Yi XU N. ELLENDT +2 位作者 xing-gang li V. UHLENWINKEL U. FRITSCHING 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第7期1636-1644,共9页
Different sized single droplets of Cu-6%Sn alloy were prepared by drop on demand(DOD)technique.The secondarydendrite arm spacing was measured and correlated with the droplet cooling rate by a semi-empirical formula.Th... Different sized single droplets of Cu-6%Sn alloy were prepared by drop on demand(DOD)technique.The secondarydendrite arm spacing was measured and correlated with the droplet cooling rate by a semi-empirical formula.The microstructure ofdroplets was observed by optical microscopy(OM)and electro backscatter diffraction(EBSD).The dendrite feature of singledroplets depends on solidification rate,cooling medium and flight distance.When droplets collide with each other at temperaturesbetween solidus and liquidus,the dendrites and grains are refined obviously possibly because the collision enhances the heat transfer.The cooling rate of colliding droplets is estimated to be more than4×104K/s based on a Newton’s cooling model.The dendritesgrow along the colliding direction because of the temperature gradient induced by the internal flow inside the droplets. 展开更多
关键词 impinging droplet secondary dendrite arm spacing cooling rate heat transfer drop on demand
下载PDF
Corrigendum to “Characterization of cooling rate and microstructure of CuSn melt droplet in drop on demand process” [Trans. Nonferrous Met. Soc. China 27 (2017), 1636.1644]
5
作者 Yi XU N. ELLENDT +2 位作者 xing-gang li V. UHLENWINKEL U. FRITSCHING 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第9期2112-2112,共1页
In the printed contribution some basic modeling equations for the droplet behavior have not been given correctly. The authors apologize for this error. The computational model used to derive the results discussed in t... In the printed contribution some basic modeling equations for the droplet behavior have not been given correctly. The authors apologize for this error. The computational model used to derive the results discussed in the paper is based on a thermal and a kinetic model for single droplet behavior in flight. The corrections are as follows. 展开更多
关键词 printed contribution DROPLET behavior
下载PDF
Mg-6Zn-3Sn合金的均匀化热处理及其对显微组织和力学性能的影响 被引量:1
6
作者 刘艳辉 马鸣龙 +4 位作者 李兴刚 李永军 石国梁 袁家伟 张奎 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2023年第1期67-78,共12页
利用DSC、OM、XRD、SEM、TEM、维氏硬度计和万能试验机,研究Mg-6Zn-3Sn合金均匀化过程中的显微组织和力学性能演变,分析合金过烧的原因和扩散动力学,确定合金的均匀化制度。结果表明,单级均匀化处理后,Mg_(2)Zn_(3)相分解,同时伴随着Mg_... 利用DSC、OM、XRD、SEM、TEM、维氏硬度计和万能试验机,研究Mg-6Zn-3Sn合金均匀化过程中的显微组织和力学性能演变,分析合金过烧的原因和扩散动力学,确定合金的均匀化制度。结果表明,单级均匀化处理后,Mg_(2)Zn_(3)相分解,同时伴随着Mg_(2)Sn相的析出。当均匀化温度上升到350℃时,Mg_(2)Zn_(3)相导致合金的过烧。合金合适的均匀化制度为(335℃,24 h)+(400℃,6 h)。在双级均匀化过程中,合金的硬度持续下降,力学性能呈现先升后降的趋势,这与Zn和Sn原子的固溶和Mg_(2)Sn相的析出有关。 展开更多
关键词 ZT63镁合金 均匀化 显微组织 扩散动力学 力学性能
下载PDF
Dislocation configuration evolution during extension twinning and its influence on precipitation behavior in AZ80 wrought magnesium alloy
7
作者 Guo-liang Shi Kui Zhang +4 位作者 xing-gang li Yong-Jun li Ming-Long Ma Jia-Wei Yuan Hong-Ju Zhang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第7期2442-2457,共16页
Thermomechanical treatment T10(extension twinning+aging treatment)can largely enhance the precipitation strengthening effect of magnesium alloys.In this study,dislocation structure evolution and precipitation behavior... Thermomechanical treatment T10(extension twinning+aging treatment)can largely enhance the precipitation strengthening effect of magnesium alloys.In this study,dislocation structure evolution and precipitation behavior during T10 treatment of an AZ80 extruded bar were analyzed mainly by two-beam diffraction in TEM.At a compressive strain of 1%in the extrusion direction(ED),a typical dislocation configuration,including basal I1 stacking faults(SFs)and<c+a>dislocations,has been established in extension twins.As the strain reaches 7%,the volume fraction of extension twins increases to more than 90%at which point high dense I1 SFs and<c+a>dislocations occur.After aging for 2 h at 150℃for the 7%strained sample,masses of basal I1 SFs and<c+a>dislocations remain in the extension twins and can act as effective nucleation sites and solute fast-diffusion channels for continuous precipitates.Consequently,the precipitates in extension twins become highly dense. 展开更多
关键词 Magnesium alloy Extension twin DISLOCATION Stacking fault Precipitation
下载PDF
Microstructure and thermophysical properties of Mg-2Zn-xCu alloys 被引量:8
8
作者 Wan-peng ZHANG Ming-long MA +4 位作者 Jia-wei YUAN Guo-liang SHI Yong-jun li xing-gang li Kui ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第7期1803-1815,共13页
The microstructure and thermophysical properties of Mg-2 Zn-x Cu alloys(x=0.5, 1.0 and 1.5, at.%) were investigated through microstructural and thermophysical characterization, heat treatment, and first-principles cal... The microstructure and thermophysical properties of Mg-2 Zn-x Cu alloys(x=0.5, 1.0 and 1.5, at.%) were investigated through microstructural and thermophysical characterization, heat treatment, and first-principles calculations. It was found that the addition of Cu had influence on the microstructure and thermophysical properties of the alloy. As the Cu content increased, the content of the MgCuZn phase increased in the as-cast alloys along with the electrical and thermal conductivities. After solution treatment, the eutectic structure partially decomposed and Zn atoms dissolved into the matrix, leading to the decrease in both the electrical and thermal conductivities of the alloy. During the early stages of the aging treatment, solute atoms precipitated from the matrix, thus increasing the electrical conductivity of the alloy. After aging for 24 h, the thermal conductivity of Mg-2 Zn-1.5 Cu alloy reached the maximum of 147.1 W/(m·K). The thermostable MgCuZn phases were responsible for increasing the electrical and thermal conductivities. Smaller amounts of Zn atoms dissolved in the matrix resulted in smaller lattice distortion and higher conductivities. The first-principles calculations findings also proved that the MgCuZn phases had very high conductance. 展开更多
关键词 Mg-Zn-Cu alloy heat treatment electrical conductivity thermal conductivity first-principles calculations
下载PDF
Microstructure and corrosion resistance of bone-implanted Mg-Zn-Ca-Sr alloy under different cooling methods 被引量:5
9
作者 He-Ning liu Kui Zhang +5 位作者 xing-gang li Yong-Jun li Ming-Long Ma Guo-liang Shi Jia-Wei Yuan Kai-Kun Wang 《Rare Metals》 SCIE EI CAS CSCD 2021年第3期643-650,共8页
The cooling gradient of Mg-3 Zn-1 Ca-0.5 Sr alloy in cast ingots under different cooling methods(air cooling,warm-water cooling and ice-water-mixture cooling) was examined and the effect of cooling rate on the structu... The cooling gradient of Mg-3 Zn-1 Ca-0.5 Sr alloy in cast ingots under different cooling methods(air cooling,warm-water cooling and ice-water-mixture cooling) was examined and the effect of cooling rate on the structure and corrosion properties was studied.The microstructure of the alloy was composed of α-Mg,Ca_(2) Mg_(6) Zn_(3) and Mg_(17)Sr_(2) phases.As the solidification cooling rate increased,the grain was refined,Zn and Sr were less segregated,the distributions of Zn and Sr were more uniform,and corrosion rate was found to first increase and then decrease;this contradicts the findings of recent research.With cooling rate increasing,the number of corroded microcouples comprising second phase and α-Mg increases.More α-Mg participates in corrosion,leading to a layered and deep corrosion pit and an increased corrosion rate.However,as the microstructure became sufficiently dense,the corroded structure protected the deep α-Mg from participating in corrosion,thus reducing the corrosion rate. 展开更多
关键词 Corrosion Mg-Zn-Ca-Sr MORPHOLOGY Cooling methods
原文传递
Microstructure and texture evolution of Mg–7Y–1Nd–0.5Zr alloy sheets with different rolling temperatures 被引量:3
10
作者 Jing-Bao liu Kui Zhang +5 位作者 Jing-Tao Han xing-gang li Yong-Jun li Ming-Long Ma Jia-Wei Yuan Guo-liang Shi 《Rare Metals》 SCIE EI CAS CSCD 2020年第11期1273-1278,共6页
The extruded Mg-7Y-1Nd-0.5Zr(wt%)alloy were performed to the same strain hot rolling with different temperatures.The microstructure and texture evolution of the sheets were investigated by optical microscopy(OM),scann... The extruded Mg-7Y-1Nd-0.5Zr(wt%)alloy were performed to the same strain hot rolling with different temperatures.The microstructure and texture evolution of the sheets were investigated by optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),and electron back-scattered diffraction(EBSD).The results indicate that the microstructure becomes homogeneous after hot rolling process and precipitated phase distributes at grain boundaries along rolling direction.With the increase in rolling temperature,the grains of sheet grow up.The sheet rolling at 400℃is composed of recrystallization grains,the necklace of the precipitated phase in the grain boundaries and excessive dislocations.The structure of necklace of the precipitated phase is fcc structure with lattice constant of a=0.75 nm.With rolling temperatures increasing from 400 to 450℃,the content of recrystallized grains in volume fraction with relatively random orientations increases significantly.Compared with the rolling process at 400℃,the amount of precipitated phases is reduced at the grain boundary,and the precipitated phase begins to appear in the grain interior when rolling at 450℃.The structure of the precipitated phase is fcc with lattice constant of a=2.22 nm.The recrystallization grains begin to grow in the rolling process at 500℃.The basal texture is obviously produced during the rolling process at 400 and 450℃;however,the basal texture is weak in the rolling process at 500℃. 展开更多
关键词 Rare earth magnesium alloy ROLLING TEXTURE Precipitated phase
原文传递
Microstructure and phase transformation of as-cast and annealed Mg–4Zn–1Y alloy containing quasi-crystal phase 被引量:8
11
作者 Yang Yang Kui Zhang +4 位作者 xing-gang li Yong-Jun li Ming-Long Ma Guo-liang Shi Jia-Wei Yuan 《Rare Metals》 SCIE EI CAS CSCD 2015年第4期239-244,共6页
By means of optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the microstructures of as-cast and heat-treated Mg--4Zn-IY ... By means of optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the microstructures of as-cast and heat-treated Mg--4Zn-IY (wt%) alloy containing quasi-crystal phase were studied. The microstructure of the as-cast alloy consists of a-Mg solid solution grains, intermetallic particles and eutectic phases (W-phase and 1-phase), and huge grains with seri- ous dendritic segregation are clearly observed. After heat treatment, phase transformation and dissolution occur in the alloy and many phases remain. When the alloy was treated above 410 ~C, the eutectic phases transform into spherical shape as the I-phase turns to W-phase. After heat treatment for long time, the alloy is over burnt and the W-phase decomposes to Mg-Y binary phase. 展开更多
关键词 Mg-Zn-Y alloy Heat treatment MICROSTRUCTURE Phase transformation Icosahedral quasi-crystal
原文传递
Homogenization heat treatment of Mg-7.0 wt%Y-1.0 wt%Nd-0.5 wt%Zr alloy 被引量:2
12
作者 Jing-Bao liu Kui Zhang +5 位作者 Jing-Tao Han xing-gang li Yong-Jun li Ming-Long Ma Jia-Wei Yuan Meng li 《Rare Metals》 SCIE EI CAS CSCD 2020年第10期1196-1201,共6页
The microstructures and mechanical properties of Mg-7.0 wt%Y-1.0 wt%Nd-0.5 wt%Zr magnesium alloy were investigated both in as-cast condition and after homogenization heat treatment by differential scanning calorimetry... The microstructures and mechanical properties of Mg-7.0 wt%Y-1.0 wt%Nd-0.5 wt%Zr magnesium alloy were investigated both in as-cast condition and after homogenization heat treatment by differential scanning calorimetry(DSC),optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM)and hardness measurement.The results indicate that the ascast alloy consists ofα-Mg matrix,Mg24 Y5 and Mg41 Nd5 phases,which are eutectic phases(cubic Y-rich phase).With the increase in homogenization temperature and time,the Mg24 Y5 and Mg41 Nd5 phases are completely dissolved into matrix,and only yttrium of intermetallic compounds leaves around boundary.After homogenization heat treatment,the elements distributed uniformly and the grains grow up not obviously,only yttrium element of intermetallic compounds left around boundary.The optimum homogenization condition is at 537℃for 16 h.The mechanical properties are improved after homogenization,with tensile strength ofσb=181 MPa,yielding strength ofσ(0.2)=144 MPa and elongation ofδ=5.5%,which are better than those of as-cast alloy. 展开更多
关键词 Rare earth magnesium alloy HOMOGENIZATION Microstructure HARDNESS
原文传递
Corrosion behaviors for peak-aged Mg-7Gd-5Y-lNd-0.5Zr alloys with oxide films 被引量:1
13
作者 Quan-Tong Jiang Kui Zhang +4 位作者 xing-gang li Yong-Jun li Ming-Long Ma Guo-liang Shi Jia-Wei Yuan 《Rare Metals》 SCIE EI CAS CSCD 2016年第10期758-762,共5页
The corrosion behaviors of T5 (225 ℃, 6.5 h) and T6 (460 ℃, 2 h + 225 ℃, 12 h) peak-aged Mg-7Gd- 5Y-1Nd-0.5Zr alloys with oxide films were investigated by optical microscope (OM), scanning electron microsco... The corrosion behaviors of T5 (225 ℃, 6.5 h) and T6 (460 ℃, 2 h + 225 ℃, 12 h) peak-aged Mg-7Gd- 5Y-1Nd-0.5Zr alloys with oxide films were investigated by optical microscope (OM), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The weight loss rates and electrochemical tests were also analyzed. The thicknesses of T5 and T6 oxide films are roughly 0.6 and 1.0 μm, respectively. The components of oxide films mainly consist of O, Mg, Y, Nd, and Gd, and the T6 oxide film results in surfaces with larger peaks than T5 oxide film. In addition, Y, Nd, and Gd peaks are all higher than those of Mg-7Gd-5Y- 1Nd-0.5Zr alloys, but Mg peak is consistently far below than that of the alloys. The specimens could be arranged in de- creasing order of corrosion rates and corrosion current densi- ties: T6 oxide film 〈 T5 oxide film 〈 T6 without oxide film 〈 T5 without oxide film. The oxide films are compact to increase the corrosion resistance for Mg-7Gd-5Y-1Nd-0.5Zr alloys, which will provide a guiding insight into the corrosion and protection of Mg-RE alloys in atmospheric environments. 展开更多
关键词 Mg-7Gd-5Y-1Nd-0.5Zr alloys Peak-aged Oxide film Corrosion behavior
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部