作者机构：
[Chen, Xiaoqun ; He, Yuehui ; Huang, Baiyun ; Qu, Xuanhui ; Lei, Changhui ] Powder Metallurgy Research Institute, Ctrl. South University of Technology, Changsha 410083, China
摘要：
The microstructure and mechanical properties of a titanium aluminide alloy, Ti-33Al-3Cr-0.5Mo, under a multi-step thermo-mechanical treatment were studied. A sub-duplex microstructure with fine equiaxial γgrains as the major phase and β<sub>2</sub>, α<sub>2</sub> as the minor phases was obtained after final heat treatment at 1250°C, for 4 h + controlled cooling. Tensile elongation for the alloy can reach 5.07% at room temperature. The principal reasons for improving elongation are the refine of grain and improvment of grain boundary structure.
作者机构：
[Huang, Han; Wang, Shiliang; Zou, Jin] School of Mechanical and Mining Engineering, University of Queensland, Brisbane, QLD 4072, Australia;[Huang, Baiyun; He, Yuehui; Wang, Shiliang; Hou, Lizhen] School of Physics and Electronics, State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China;[Auchterlonie, Graeme John; Zou, Jin] Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, QLD 4072, Australia
通讯机构：
[Wang, SL] Cent S Univ, Sch Phys & Elect, State Key Lab Powder Met, Changsha 410083, Peoples R China.
关键词：
Flat substrates - Fracture analysis - High strains - In-situ TEM - Intrinsic strength - Nanoscale whiskers - Possible mechanisms
期刊：
Materials and Design,2009年30(3):857-861 ISSN：0261-3069
通讯作者：
Song, M.(Min.Song.Th05@Alum.Dartmouth.ORG)
作者机构：
[ Huang, Baiyun ; Song, Min ; He, Yuehui ; Xiao, Daihong ] State Key Laboratory of Powder Metallurgy, Central South University, Lushan South Road, Changsha, 410083, China
通讯机构：
[Song, M] Cent S Univ, State Key Lab Powder Met, Lushan S Rd, Changsha 410083, Peoples R China.
作者：
Wang, Shiliang;He, Yuehui;Liu, Xinli;Huang, Han;Zou, Jin;Song, Min;Huang, Baiyun;Liu, C. T.
期刊：
NANOTECHNOLOGY,2011年22(40) ISSN：0957-4484
通讯作者：
He, YH
作者机构：
[Huang, Baiyun; He, Yuehui; Wang, Shiliang; Song, Min; Liu, Xinli] State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China;[Liu, C. T.] Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong;[Zou, Jin; Huang, Han] School of Mechanical and Mining Engineering, Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, QLD 4072, Australia
通讯机构：
[He, YH] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.
关键词：
Cu nanowires - Electronic device - Field emission property - Low temperatures - Nanocable arrays - Nanocables - Oxidization - Top surface
期刊：
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering,2014年43(6):1492-1496 ISSN：1002-185X
通讯作者：
Zhang, JH
作者机构：
[Xu Yajuan; Zhang Junhong] Department of Materials Science and Engineering, Luoyang Institute of Science and Technology, Luoyang 471023, China;[He Yuehui; Huang Baiyun] State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China
通讯机构：
[Zhang, JH] Luoyang Inst Sci & Technol, Dept Mat Sci & Engn, Luoyang 471023, Peoples R China.
关键词：
TiAl based alloys;superplastic deformation;mechanism of rate controlling
摘要：
Superplastic mechanical behavior of Ti-48Al-2.3Cr-0.2Mo (at%) alloy with deformed microstructure was investigated at temperatures ranging from 800 to 1100°C with strain rates between 5(10<sup>-5</sup> and 1(10<sup>-3</sup> s<sup>-1</sup> by constant strain rate tests and incremental strain rate tests. Depending on the plots of true stress-true strain and the data of activation energy calculated in the tests, the mechanism of superplasticity was discussed. Results show that for the Ti-48Al-2.3Cr-0.2Mo alloy, there is almost no constant stress stage but hardening is observed in the plots of true stress-true strain. Particularly, at the temperatures above 1025°C or strain rates below 5(10<sup>-4</sup> s<sup>-1</sup>, a continuous strain hardening stage is observed, and with the increasing of the temperature and the decreasing of the strain rate, the stage increases. High-density dislocation caused by pre-deformation is suggested the reason of hardening. At temperatures from 800 to 900°C, the maximum strain rate sensitivity (m) values are 0.52~0.67, and the activation energy of the alloy is calculated as Q<inf>app</inf> =178 kJ/mol, indicating that the dominant mechanism of superplastic deformation is grain boundary siding controlled by grain boundary diffusion. At temperatures from 950 to 1100°C, the maximum strain rate sensitivity (m) values are 0.63~0.77, and the activation energy of the alloy is calculated as Q<inf>app</inf> =290 kJ/mol, suggesting that the dominant mechanism of superplastic deformation is grain boundary siding controlled by lattice diffusion.
期刊：
International Journal of Refractory Metals and Hard Materials,2003年21(5-6):227-231 ISSN：0263-4368
通讯作者：
He, YH
作者机构：
[Chen, LB; Huang, BY; He, YH] Stt. Key Lab. for Powder Metallurgy, Central South University, Changsha, Hunan 410083, China;[Liaw, PK] Dept. of Mat. Sci. and Engineering, University of Tennessee, Knoxville, TN 37996-2200, United States
通讯机构：
[He, YH] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.
关键词：
Recycled alloy powders
摘要：
The processes of direct recycling heavy metal turnings by oxidation-reduction technique have been investigated in details. The average particle size of recycled alloy powders was about 1.5 mum, and the shape of powder particle was regular when the final reduction temperature was 850 degreesC. The average size of the particle increased to 5 and 8 mum when increasing the reduction temperature to 900 and 950 degreesC, respectively. However, if the reduction temperature was above 900 degreesC, the surface of powder was complicated. Increasing reduction temperature from 900 to 950 degreesC, the particle of recycled powder grew slightly, and the content of oxygen decreased from 0.2314% to 0.1700%. It has been also found that the chemical composition of the recycled alloy powder is the same as the primary heavy metal turnings. (C) 2003 Elsevier Ltd. All rights reserved.
摘要：
FeAl/TiC composites were fabricated by reactive hot-pressing of blended elemental powders. The effects of TiC content, composition of the binder phase and Ni alloying on densification process and mechanical properties were studied. Results showed that with the increase of TiC content, densities of the composites decreased, and hardness, and bend strength showed peak values. It was beneficial to densification by adding more Al in the binder phase, however it deteriorated mechanical properties due to excessive oxides and thermal vacancies. The addition of Ni improved the densities and mechanical properties of the composites by three effects: promoting mass transfer during liquid phase sintering, reducing sintering expansion of FeAl and solution-strengthening the bonding phase.
期刊：
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2014年619:265-273 ISSN：0921-5093
通讯作者：
Liu, Y
作者机构：
[Liu, Bin; He, Yuehui; Liang, Xiaopeng; Liu, Yong; Gan, Ziyang] State Key Laboratory of Powder Metallurgy, Central South University, Changsha, China;[Li, Huizhong] School of Materials Science and Engineering, Central South University, Changsha, China
通讯机构：
[Liu, Y] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
关键词：
TiAl intermetallics;Microstructure;Mechanical properties;Hot pack-rolling
摘要：
The microstructural and mechanical properties of powder metallurgical (PM) Ti-47Al-2Cr-0.2Mo alloy plates under various hot pack-rolling conditions were investigated. The PM TiAl plates show recrystallized and duplex microstructure. The dynamic recrystallization mainly occurred in beta phase at the beginning of deformation, and a large amount of dislocations and sub-grains formed in gamma phase. The dynamic recrystallization of gamma phase is the main mechanism for the flow softening in the later stage of the hot rolling. The optimum parameters for hot rolling PM TiAl are obtained by adjusting temperatures, speeds and reduction per pass. Based on the microstructures after a certain reduction, a roll-speed-increase hot rolling is developed for effectively producing TiAl alloy plates. Once fine and uniform duplex microstructure was obtained after the first stage of deformation, the TiAl alloy can be further rolled at a lower temperature, higher speed and larger reduction per pass. The ultimate strength, yield strength and elongation of the plate fabricated though the new process are 682 MPa, 639 MPa and 1.32%, respectively, which are higher than those of plated produced by the constant-speed rolling. (C) 2014 Elsevier B.V. All rights reserved.
作者机构：
[ Wang, Yan ] School of Aeronautics and Astronautics, Central South University, Changsha 410083, China;[ Cao, Peng ] Department of Chemical and Materials Engineering, University of Auckland, Private Bag 92019, Auckland, New Zealand;[ Liu, Bin ; Zhou, Canxu ; He, Yuehui ; Xiang, Chunjie ; Li, Jianbo ; Liu, Yong ] State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
通讯机构：
[Liu, Y] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
关键词：
Apparent activation energy - Based on TiAl - Deformation conditions - Deformation map - High temperature compressive deformations - High temperature deformation behavior - Isothermal forging - Recrystallized grains
作者机构：
[Wang, Yan] School of Aeronautics and Astronautics, Central South University, Changsha 410083, China;[Liu, Bin; He, Yuehui; Zhao, Kun; Li, Jianbo; Liu, Yong] State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
通讯机构：
[Liu, Y] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
关键词：
Titanium aluminides, based on TiAl;Deformation map;Microstructure
期刊：
JOURNAL OF MATERIALS SCIENCE,2016年51(5):2594-2597 ISSN：0022-2461
通讯作者：
Liu, XL
作者机构：
[Liu, Xinli; He, Yuehui; Jiang, Yao; Zhang, Qiankun; Zhang, Huibin] State Key Laboratory of Powder Metallurgy, Central South University, Changsha, China;[Liu, Xinli] School of Metallurgical Engineering, Hunan University of Technology, Zhuzhou, China
通讯机构：
[Liu, XL] Hunan Univ Technol, Sch Met Engn, Zhuzhou 412007, Peoples R China.
期刊：
International Journal of Hydrogen Energy,2014年36(19):12112-12120 ISSN：0360-3199
通讯作者：
He, Yuehui
作者机构：
[ Huang, Baiyun ; Dong, Hongxing ; He, Yuehui ; Lei, Ting ] State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan, China;[ Liu, C.T. ] Department of Mechanical Engineering, Hong Kong Polytechnic University, Hong Kong, Hong Kong;[ Xu, Nanping ] Membrane Science and Technology Research Center, Nanjing University of Technology, Nanjing, China;[Dong, Hongxing ] Institute of Electro-Mechanical, Hangzhou Polytech, Hangzhou, Zhejiang, China
摘要：
Porous Ni<inf>3</inf>Al intermetallic material with a mean pore diameter of around 1 μm was prepared by step sintering Ni and Al powder pressed compacts in vacuum furnace at 900 °C. The electrocatalytic activity of the as-fabricated porous Ni<inf>3</inf>Al material as an electrode for hydrogen evolution reaction (HER) in alkaline solutions was investigated by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) techniques. It is found that the onset potential of porous Ni<inf>3</inf>Al for HER shifted in the positive direction favoring hydrogen generation with lower overpotential, compared with foam Ni and dense Ni electrodes. Effects of electrolyte concentration and temperature on HER as well as the electrochemical stability in alkaline solution were investigated and the electrochemical activation energy was determined for the porous Ni<inf>3</inf>Al. The increased activity for HER was attributed to the high porosity, an increased electrochemical surface area and the nanostructure of porous Ni<inf>3</inf>Al electrode. The corrosion tests showed that the corrosion resistance of porous Ni<inf>3</inf>Al electrode changed during the immersion process due to the formation of passive film layers.
作者：
Liu, Chao;Lin, Nan;He, Yuehui;Wu, Chonghu;Jiang, Yao
期刊：
Journal of Alloys and Compounds,2014年594:76-81 ISSN：0925-8388
通讯作者：
Lin, N.(linnan@csu.edu.cn)
作者机构：
[ Lin, Nan ; Jiang, Yao ; He, Yuehui ; Liu, Chao ; Wu, Chonghu ] State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
通讯机构：
[Lin, N] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
关键词：
Cemented carbides - Fracture toughness values - Mechanical properties test - Microstructure and mechanical properties - Microstructure and properties - Sintering process - Structural applications - Transgranular fracture
期刊：
Transactions of Nonferrous Metals Society of China,1998年8(1):48-51 ISSN：1003-6326
通讯作者：
He, Yuehui
作者机构：
[ Huang, Baiyun ; Liu, Yong ; He, Yuehui ] Cent S Univ Technol, Powder Met Res Inst, Changsha 410083, Peoples R China.
关键词：
Viscous rheologic superplastic technique
摘要：
A new viscous-rheologic superplastic technique for TiAl based alloy has been explored successfully, which can be divided into three stages: accelerated deformation at large load, viscous-rheologic deformation at low load and final deformation at increasing load. In the above stages, three respective deformation mechanisms exist: coerced grain boundary movement, grain boundary viscous-rheologic sliding and grain boundary sliding aided by sliding inside grains. The damage of recrystallization and neck shrinkage on superplasticity can be avoided by using technique.
期刊：
Transactions of Nonferrous Metals Society of China,1998年8(3):397-402 ISSN：1003-6326
通讯作者：
Liu, Yong
作者机构：
[ Wang, Bing ; Huang, Baiyun ; He, Yuehui ; Liu, Yong ] Cent S Univ Technol, Powder Met Res Inst, Changsha 410083, Peoples R China.
关键词：
Reactive diffusion
摘要：
Elemental Ti and Al powders were hot pressed in Ar atmosphere at various temperatures to produce Ti-48Al (%) alloy. The microstructure evolution was studied. The results show that the reaction between Ti and AL is mainly controlled by diffusion.After hot pressing at 800 °C, the reaction Ti and Al powders is incomplete. The higher the hot pressing temperature is, the higher the rate of reactive diffusion and the more complete the crystallization of TiAl and Ti<inf>3</inf>Al will be. After hot pressing at 1300 °C, the Ti<inf>3</inf>Al phase is island like. After hot pressing at 1400 °C, there are large γgrains and coarse lamellar microstructure. So 1300 °C seems to be the premium temperature for the reaction synthesis of TiAl based alloy.
作者：
Yong-dan Hou 侯永丹;Yao Jiang 江垚;Ting Lei 雷霆;Yue-hui He 贺跃辉
期刊：
Journal of Central South University of Technology (English Edition),2011年18(4):966-971 ISSN：1005-9784
通讯作者：
Jiang, Y.(jiangyao@mail.csu.edu.cn)
作者机构：
[Yong-dan Hou 侯永丹; Yao Jiang 江垚; Yue-hui He 贺跃辉; Ting Lei 雷霆] State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
通讯机构：
[Jiang, Y] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.
期刊：
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2010年527(24-25):6537-6542 ISSN：0921-5093
通讯作者：
Song, M
作者机构：
[He, Yuehui; Song, Min; Xiao, Daihong; Sun, Chao; Wang, Zhangwei] State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
通讯机构：
[Song, M] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.
摘要：
This paper studied the combined effects of extrusion and reinforcement volume fraction on the mechanical properties of SiC particles reinforced Al-Cu alloy composites. It has been shown that extrusion can improve the distributed homogeneity of the SiC particles in the matrix and enhance the interfacial bonding strength of the composites. The hardness of the composites increased with increasing the volume fraction of the SiC particles, while the yield strength and tensile strength of the composites decreased with increasing the volume fraction of the SiC particles due to the particle fracture during extrusion. It has also been shown that the hardness increased with the aging time until reaching the maximum values, after which the hardness started to decrease. Fracture surface observations showed that the dominant fracture mechanism of the composites is ductile fracture of the matrix, accompanied by the pull-out of the particles from the matrix before extrusion or by the SiC particle fracture after extrusion, respectively. (C) 2010 Elsevier B.V. All rights reserved.
