Liping ZHENG Xiqing XIA Mingyao LI Shanghai Institute of Nuclear Research
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Academia Sinca
,
Shanghai
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201800
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ChinaRisheng LI Lab.of Atomic Imaging of Solids
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Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China
材料科学技术（英文）
Correlations between surface composition changes and ion bombardment fluences were studied for multicomponent materials by using a dynamic Monte Carlo program,including the preferential sputtering and bombardment-induced Gibbsian segregation (BIGS) processes.For the case of 1 keV KR-~(10)B_(0.02)~(11)B_(0.08) (the most simple multicomponent material system),it is found that the ~(10)B composition enriches at the surface at low fluences but depletes at the surface at high fluences.For the case of 1 keV Ar-Pt_(0.5)Cu_(0.5).it is found that the Cu composition at the topmost surface is always under the bulk composition between zero and high fluences,but the evident composition gradient of Cu(the segregation species) exists in the surface at low fluences.The effects of the preferential sputtering and BIGS processes on above two surface composition profiles are also discussed.
关键词:
implantation
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null
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Yourong XU Deying WANG Qi JIN Yijian ZHOU Shanghai University of Science and Technology
,
Shanghai
,
201800
,
ChinaFan HU Chao LIU Iron and Steel Research Institute of Baoshan Iron and Steel Complex
,
Shanghai
,
201900
,
China
材料科学技术（英文）
By means of electron probe(EPMA),scanning electron microscope(SEM),and optical microscope (QM),the diffusion behaviour on the Fe-Cu interface of copper brazed double-wall steel tubes and the microstructure of the diffusion layer have been investigated.There are three kinds of metallurgical bonds between copper plating layer and steel substrate: (1)the Cu diffusing into steel substrate along grain boundary of ferrite;(2)the Cu diffusion into grain bulk of ferrite: (3)the Fe diffusing into Cu layer.The copper brazed double-wall steel tubes are formed by the combination of the diffusions mentioned above and this is the reason for excellent mechanical and technological properties of the copper brazed double-wall steel tubes.
关键词:
metallurgical bond
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null
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null
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