U. Brill
金属学报(英文版)
The use of high-temperature materials is especially important in power station construction, heating systems engineering, furnace industry, chemical and petrochemical industry, waste incineration plants, coal gasification plants and for flying gas turbines in civil and military aircrafts and helicopters. Particularly in recent years, the development of new processes and the drive to improve the economics of existing processes have increased the requirements significantly so that it is necessary to change from well-proven materials to new alloys. Hitherto, heat resistant ferritic steels sufficed in conventional power station constructions for temperatures up to 550℃ newly developed ferritic/martensitic steels provide sufficient strength up to about 600-620℃. In new processes, e.g. fluidized-bed combustion of coal, process temperatures up to 900℃ occur. However, this is not the upper limit, since in combustion engines, e.g. gas turbines. Material temperatures up to 1100℃ are reached locally. Similar development trends can also be identified in the petrochemical industry and in the heat treatment and furnace engineering. The advance to ever higher material temperatures now not only has the consequence of having to use materials with enhanced high-strength properties, considerable attention now also has to be given to their chemical stability in corrosive media. Therefore not only examples of the use of high-temperature alloys for practical applications will be given but also be contributed to some general rules for material selection with regard to their high-temperature strength and corrosion resistance.
关键词:
nickel-based alloy
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null
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null
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.
关键词:
room-temperature
Computer Physics Communications
Based on a detailed check of the LDA + U and GGA + U corrected methods, we found that the transition energy levels depend almost linearly on the effective U parameter. GGA + U seems to be better than LDA + U, with effective U parameter of about 5.0 eV. However, though the results between LDA and GGA are very different before correction, the corrected transition energy levels spread less than 0.3 eV. These more or less consistent results indicate the necessity and validity of LDA + U and GGA + U correction. (C) 2012 Elsevier B.V. All rights reserved.
关键词:
Band-gap problems;LDA plus U and GGA plus U;ZnO;First-principles;augmented-wave method
鲜晓斌
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刘柯钊
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吕学超
,
张永彬
稀有金属材料与工程
用循环Ar+轰击-磁控溅射离子镀(MSIP)法在U表面上镀Al,Ti/Al,并采用俄歇电子能谱仪(AES)、扫描电镜(SEM)、电化学实验和平面磨耗实验,研究了其表面、剖面形貌和耐磨耐蚀性能,以及Al/U和Ti/Al镀层界面.结果表明:U上循环Ar+轰击-磁控溅射离子镀Al,Ti/Al界面存在较宽的原子共混区,且Ti/Al镀层的耐磨耐蚀性能明显优于单一磁控溅射离子镀Al层.
关键词:
Ti/Al镀层
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界面
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耐磨性
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耐蚀性
伏晓国
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刘柯钊
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汪小琳
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柏朝茂
,
赵正平
,
蒋春丽
金属学报
采用X射线光电子能谱(XPS)分析研究了298 K时O2在金属U和U Nb合金清洁表面的原位吸附过程,作为对照还研究了在纯Nb表面的吸附.吸附各阶段XPS图谱的变化揭示了O2在U,Nb和U-Nb合金表面的吸附将导致UO2,NbO和Nb2O5等多种产物形成定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45 L和40 L(1 L=L33x10-4Pa.s),而O2在金属Nb上的饱和吸附量仅约为10 L.
关键词:
合金
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null
,
null
伏晓国
,
刘柯钊
,
汪小琳
,
柏朝茂
,
赵正平
,
蒋春丽
金属学报
doi:10.3321/j.issn:0412-1961.2001.06.004
采用X射线光电子能谱(XPS)分析研究了298 K时O2在金属U和U Nb合金清洁表面的原位吸附过程,作为对照还研究了在纯Nb表面的吸附.吸附各阶段XPS图谱的变化揭示了O2在U,Nb和U-Nb合金表面的吸附将导致UO2,NbO和Nb2O5等多种产物形成定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45 L和40 L(1 L=L33x10-4Pa@s),而O2在金属Nb上的饱和吸附量仅约为10 L.
关键词:
O2
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U
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U-Nb合金
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表面吸附
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X射线光电子谱
