Jie Chen
,
Chong-Gao Bao
,
Yong Wang
,
Jin-Ling Liu
,
Challapalli Suryanarayana
金属学报(英文版)
doi:10.1007/s40195-015-0333-6
Magnesium matrix composites reinforced with AlN particles were fabricated by the powder metallurgy technique. The evolution of lattice constants and solid solubility levels of Al in α-Mg and the microstructure of Mg-Al/AlN composites were investigated in the present study. The results showed that the solid solubility of Al in α-Mg reached a relatively high level by the P/M process with a long time of milling. X-ray diffraction showed that the peaks of Mg phase clearly shifted to higher angles. The lattice constants and cell volume decreased significantly compared with those of standard Mg due to a significant amount of Al incorporated into α-Mg in the form of substitutional solid solution. The degree of lattice deformation decreased at a low sintering temperature and increased at higher sintering temperatures due to the presence of AlN. Microstructural characterization of the composites revealed a necklace distribution of AlN particles in the Mg matrix. Heat treatment led to precipitation of Mg17Al12 from the supersaturated α-Mg solid solution. The precipitate exhibited granular and lath-shaped morphologies in Mg matrix and flocculent precipitation around AlN particles.
关键词:
Metal matrix composite
,
AlN particle
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Microstructure
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Lattice parameter
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Powder metallurgy
,
Solid solubility
李开明
,
李亚洲
,
冯维贵
,
林长
量子电子学报
doi:10.3969/j.issn.1007-5461.2007.05.014
采用非线性反馈控制,用附加了带参数的正弦项对Chen系统进行了有效的控制.随着参数k的逐渐增大,系统的动力学行为呈现出一系列的变化.数值研究结果表明:随控制参数的增大,驱动信号的强度渐大,混沌系统由混沌运动到周期轨道,最终到一相点.
关键词:
混沌
,
Chen系统
,
不动点
,
Lyapunov指数
,
反馈控制
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
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room-temperature
Nuclear Engineering and Design
Liquid droplet erosion (LDE), which often occurs in bellows made of nickel-based alloys, threatens the security operation of the nuclear power plant. As the candidate materials of the bellows, Inconel 600 and Inconel 625 were both tested for resistance to cavitation erosion (CE) and jet impingement erosion (JIE) through vibratory cavitation equipment and a jet apparatus for erosion-corrosion. Cumulative mass loss vs. exposure time was used to evaluate the erosion rate of the two alloys. The surface and cross-sectional morphologies before and after the erosion tests were observed by scanning electron microscopy (SEM), the inclusions were analyzed by an energy dispersive spectroscopy (EDS), and the surface roughness was also measured by surface roughness tester to illustrate the evolution of erosion process. The results show that the cumulative mass loss of CE of Inconel 625 is about 1/6 that of Inconel 600 and the CE incubation period of the Inconel 625 is 4 times as long as that of the Inconel 600. The micro-morphology evolution of CE process illustrates that the twinning and hardness of the Inconel 625 plays a significant role in CE. In addition, the cumulative mass loss of JIE of Inconel 625 is about 2/3 that of Inconel 600 at impacting angle of 90 degrees, and almost equal to that of the Inconel 600 at impacting angle of 30 degrees. Overall, the resistance to CE and JIE of Inconel 625 is much superior to that of Inconel 600. (C) 2010 Elsevier By. All rights reserved.
关键词:
stress-corrosion cracking;aluminide intermetallic alloys;high-purity;water;mechanical-properties;crevice corrosion;solid particles;wear;behavior;microstructure;deformation;steam
金属学报
Volu扣ne 27SeriesB1991AUTHOR INDEX CCAO Guanghan(曹光旱)············……6一B科6CAo weijie(曹卫恋)..················……5一B32oCAO Yilin(曹益林)··················……6一B443CHANG Xin(常听)···············……1一B48CHE Guang邻n(车广灿)·············一6一B科0CHEN Erbao(陈二保)···············……6一B410CHEN Jia....
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Nuclear Engineering and Design
A composite coating was deposited on Inconel 600 substrate by cold spray method using pure Ni powder (60 wt.%) blended with alpha-Al(2)O(3) (40 wt.%) as feedstock. It is expected to be applied to repair the bellows eroded by the liquid droplet erosion (LDE). Microstructure of the coating was observed using optical microscope (OM) and scanning electron microscopy (SEM). Microhardness of the coating was determined by Vickers hardness tester. Cavitation erosion (CE) experiments were carried out in the distilled water. Jet impingement erosion (JIE) experiments were performed in slurry containing 1 wt.% quartz particle with the flow velocity of 15 m/s at impingement angles of 30 degrees, 60 degrees and 90 degrees, respectively. Cumulative mass loss vs. testing time was used to evaluate the erosion rate of the coating. The erosion mechanism was analyzed by OM, SEM, X-ray diffraction (XRD) and the microhardness measurement. The results show that the composite coating has compact microstructure and relatively high hardness. The resistance to CE of the coating is not as good as that of Inconel 600 substrate due to the weak bonds of the Al(2)O(3) particles. However, the results of the JIE test indicate that the slurry erosion resistance of the coating is better than that of Inconel 600 at the impact angles of 30 degrees and 60 degrees, but not at the normal impact angle. (C) 2011 Elsevier B.V. All rights reserved.
关键词:
large powder particles;composite coatings;slurry erosion;kinetic;spray;liquid impact;alloy;microstructure;steels;deposition;resistance
高诚
,
胥蕊娜
,
陈黎
,
姜培学
工程热物理学报
格子Boltzmann方法(LBM)在计算复杂结构物理模型时具有独特优势并在模拟两相流动过程中能够高效清晰捕捉相界面.本文介绍了基于Shan-Chen多相模型的格子Boltzmann方法的理论成果以及基于二氧化碳封存的超临界两相流的模拟研究.结果表明,Shan-Chen模型在模拟两相流时符合Laplace定律,且两相层流时的速度分布和相渗曲线均与理论值吻合.二氧化碳封存过程中,较大的注入速率在提高二氧化碳残余俘获量的同时会降低其化学俘获量.
关键词:
二氧化碳封存
,
超临界两相流
,
Shan-Chen模型
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....
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