R.Gibala H.Chang C.M.Czarnik K.M.Edwards A.Misra Department of Materials Science and Engineering
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University of Michigan
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Ann Arbor
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Michigan 48109-2136
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USA
材料科学技术（英文）
This paper demonstrates that plasticity enhancement processes previously observed in bcc metals and associated with the presence of surface films and precipitates or dispersoids are operative in or- dered intermetallic compounds.' Some specific results are given for NiAl-and MoSi_2-based materials.The plasticity of NiAl and related B2 ordered alloys at room temperature during monotonic deformation can be enhanced by application of surface films such as electroless nickel platings.Sig- nificant effects are also observed during cyclic deformation.The presence of ductile second phases such as fcc γ or the ordered phase γ' introduced by alloying also enhances the plasticity of NiAl. MoSi_2 exhibits similar effects of surface films and second phases,but primarily at elevated tempera- tures,T>900℃.In this paper,we illustrate the effects of ZrO_2 surface films deposited near room temperature and TiC particulate additions introduced by powder processing techniques.In all cases, the plasticity enhancement is associated with enhanced dislocation generation processes under the conditions of constrained deformation at the film-substrate or precipitate/dispersoid-matrix inter- face of the composite system.
关键词:
plasticity
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周秋香
,
张少峰
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宋海斌
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岳琳
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王延吉
人工晶体学报
doi:10.3969/j.issn.1000-985X.2004.03.028
在中温水热反应条件下,以CoCl2·6H2O、2,6-萘二羧酸(2,6-pda)和4,4'-bpy为原料,合成了一种二维互穿配位聚合物[Co3(2,6-nda)3(4,4'-bpy)1.5]n晶体,对其进行了元素分析、红外光谱表征、TGA-GTA分析和X射线单晶衍射测定.该配位聚合物属单斜晶系,C2/m空间群,晶胞参数为a=1.7285(11)nm,b=1.9965(13)nm,c=1.3994(9)nm,α=90°,β=95.822(11)°,γ=90°,V=4.804(5)nmm3,Z=4,dc=1.457g/cm3,μ=1.089mm-1,F(000)=2136,R1=0.0594,wR2=0.1605.结果显示形成一个二维互穿的网络结构.
关键词:
水热合成
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二维互穿配位聚合物
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晶体结构
