LIU Jianhong HE Shiyu YAO Mei Harbin Institute of Technology
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Harbin
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China lecturer
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Depatment of Metallic Materials
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Harbin Institute of Technology
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Harbin 150006
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China
金属学报(英文版)
The growing process of thermal fatigue cracking,in steel 3Cr2WSV was observed under desk SEM fitted with sell-made minisized device for thermal faligue test.Before the growing of thermal fatigue crack,the main crack tip reveals to blunt firstly,and some holes and uncontinuous microcraeks occur in front of it.The growth is developed by bridging of main crack together with holes and microcracks.
关键词:
steel 3Cr2W8V
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null
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null
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null
ZHANG Lei WANG Peixuan TAO Rong MA Ruzhang ZHANG Guoguang University of Science and Technology Beijing
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Beijing
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China professor
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Department of Materials Physics.University of Science and Technology Beijing.Beijing 100083
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China
金属学报(英文版)
Nucleation and growth of He bubbles at different annealing temperatures T≤1023 K in stain- less steels HR-2 and SS321,implanted with He~+(40-70 keV.1×10~(16)-6× 10~(17) He~+/cm~2),were ohserved under TEM.T=0.45T_m seems to be a transition temperature.The He bubbles continue mainly their nucleation at 0.3T_m< T<0.45T_m,and grow predominantly at T≥0.45T_m,due probably to migration and coalescence by surface diffusion of metal atoms around the bubbles.The apparent activation energies for the growth are found to he 0.41 and 0.31 eV for HR-2 and SS321 respectively.The bubble density in HR-2 is greater than that in SS321 within whole measuring temperature range,and the onset temperature of rapid swelling is also higher.It is believed that the resistance of HR-2 to He is superior to that fo SS321.
关键词:
stainless steel
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null
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null
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null
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null
D.Eylon
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S.R.Seagle
材料科学技术（英）
The state of Ti research, development and industry is reviewed in this article. The fifty-year anniversary of Ti technology commercialization in the USA provides an opportunity for a historical perspective. Incorporation of "information-age" tools into alloy development, processing, and production invigorates the technology. Consolidation, diversification and globalization have been transforming the Ti industry in the recent years.
关键词:
WU Chuansong
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CAO Zhenning
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WU Lin Harbin Institute of Technology
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Harbin
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China
金属学报(英文版)
A model is established to analyze three-dimensional fluid flow and heat transfer in TICweld pools with full penetration.It considers the deformation of the molten pool surfaceat the condition of full penetrated workpieees,takes the are pressure as the drivingforce of the pool surface deformation,and determines the surface configuration of weldpool based on the dynamic balance of arc pressure,pool gravity and surface tension atdeformed weld pool surface. The SIMPLER algorithm is used to calculate the fluid flowfield and temperature distribution in TIG weld pools of stainless steel workpieces.TIGwelding experiments are made to verify the validity of the model.It shows the calculatedresults by the model are in good agreement with experimental measurements. professor,Dept of Welding Engineering,Harbin Institute of Technology,Harbin 150006,China
关键词:
KEY WORDS TIG weld pool
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null
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null
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null
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null
李悦
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邓爱红
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刘莉
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王康
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谢莎
材料研究学报
利用x射线衍射(xRD)和慢正电子束分析(SPBA)技术研究高温退火后含He钛膜的微观结构和钛膜内He相关缺陷的演化.XRD分析表明,高温退火后Ti和Si在高温下发生反应形成稳定的多晶TiSi2化合物,He原子的掺入会影响TiSi2晶体的择优取向,而对TiSi2晶粒尺寸的影响较小.SPBA结果表明,室温下,钛膜内的缺陷浓度或尺寸会随着掺He浓度的增加而增大;高温退火后,当He浓度小于5％(原子分数,下同)时(除2％外),钛膜内的He相关缺陷浓度随着He浓度增加相应地增加.当He浓度增加到14％时,高温会使较高浓度的He原子、He-空位复合体以及小He泡迁移聚集形成一些尺寸较大He泡,而较大He泡周围与He相关的小尺寸缺陷的浓度则会发生相应地减少.
关键词:
金属材料
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含He钛膜
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直流磁控溅射
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He相关缺陷
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XRD
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SPBA
施立群
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金钦华
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刘超卓
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徐世林
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周筑颖
原子核物理评论
doi:10.3969/j.issn.1007-4627.2005.01.045
研究了用He/Ar混合溅射气体的直流磁控溅射制备钛膜中He的掺入现象.分析结果表明,大量的He原子(He/Ti原子比高达56%) 被均匀地引入到Ti膜中,He含量可由混合溅射气体的He分量精确控制.通过调节溅射参数,可实现样品中He的低损伤引入.研究还发现,溅射沉积的含氦Ti膜具有较高的He成泡剂量和高的固He能力,这可能是溅射沉积形成了纳米晶Ti膜所致.纳米晶Ti膜较粗晶材料具有很高浓度的He捕陷中心,使He泡密度增大而泡尺寸减小.随He引入量的增加,Ti膜的晶粒尺寸减小,He引起的晶体点阵参数和X射线衍射峰宽度增大,晶体的无序程度增加.
关键词:
氦
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损伤
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泡
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钛膜
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溅射沉积
Intermetallics
The well-densified Ni(3)Al alloys without and with boron addition were fabricated by self-propagation high-temperature synthesis and hot extrusion (SHS/HE) technology. Microstructure investigation showed that Ni(3)Al and Ni(3)Al-1B alloys contained fine grain structure. Analysis of X-ray spectra as well as transmission electron microscopy studies revealed that three phases present in all alloys: gamma-Ni, Ni(3)Al and dispersoids of alpha- Al(2)O(3) and gamma- Al(2)O(3). However, beta-NiAl, Ni(3)B phase and twinned Ni(3)Al crystal are observed in the Ni(3)Al-1B alloy. In addition, dislocations with high density exist in all alloys. The mechanical test showed that the B addition leads to obvious improvement in yield strength and compressive ductility, and compared with the ones synthesized by combustion, SHS/HE synthesized Ni(3)Al and Ni(3)Al-1B alloys exhibit more excellent mechanical properties. (C) 2010 Elsevier Ltd. All rights reserved.
关键词:
Nickel aluminides, based on Ni(3)Al;Mechanical properties at ambient;temperature;Reaction synthesis;Microstructure;combustion synthesis;nickel;aluminides;boron
冯文天
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马新文
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朱小龙
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张少峰
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刘惠萍
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李斌
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闫顺成
原子核物理评论
利用反应显微成像谱仪对70和100 keV He2+与He原子碰撞转移电离(TI)过程中不同出射角度的电子能谱进行了测量,观测到出射电子能谱具有如下分布特征:出射电子速度分布介于0和入射离子速度νp之间;在不同出射角度电子能谱分布均有一极大值存在,随着出射角度的增大,能谱分布极大值逐渐减小; 当电子出射角度等于45°时,多数电子集中在0 eV附近.上述特征可由低能离子-原子碰撞"准分子"模型进行定性解释.在100 keV He2+-He转移电离出射电子能谱中有靶电子被俘获至散射离子连续态(electron capture to continuum,简称ECC)电子的贡献,这可看做是动力学两步过程的作用.
关键词:
反应显微谱仪
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转移电离
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ECC电子
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"准分子"模型
