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Layer Thickness-Dependent Hardness and Strain Rate Sensitivity of Cu-Al/Al Nanostructured Multilayers

Ya-Qiang Wang , Zhao-Qi Hou , Jin-Yu Zhang , Xiao-Qing Liang , Gang Liu , Guo-Jun Zhang , Jun Sun

金属学报(英文版) doi:10.1007/s40195-016-0372-7

Cu-Al/Al nanostructured metallic multilayers with Al layer thickness h Al varying from 5 to 100 nm were prepared, and their mechanical properties and deformation behaviors were studied by nanoindentation testing. The results showed that the hardness increased drastically with decreasing h Al down to about 20 nm, whereafter the hardness reached a plateau that approaches the hardness of the alloyed Cu-Al monolithic thin films. The strain rate sensitivity (SRS, m), however, decreased monotonically with reducing h Al. The layer thickness-dependent strengthening mechanisms were discussed, and it was revealed that the alloyed Cu-Al nanolayers dominated at h Al ≤ 20 nm, while the crystalline Al nanolayers dominated at h Al > 20 nm. The plastic deformation was mainly related to the ductile Al nanolayers, which was responsible for the monotonic evolution of SRS with h Al. In addition, the h Al-dependent hardness and SRS were quantitatively modeled in light of the strengthening mechanisms at different length scales.

关键词: Nanostructured , films , Cu-Al/Al , multilayers , Hardness , Strain , rate , sensitivity , Layer , thickness , dependence

Interfacial Structures Governed Plastic Deformation Behaviors in Metallic Multilayers

Ming-Zhen Wei , Zhen-Hua Cao , Xiang-Kang Meng

金属学报(英文版) doi:10.1007/s40195-016-0377-2

In this work, we have investigated the mechanical properties of Cu/Ta, Ag/Cu and Ag/Nb multilayers with different heterogeneous interfaces. The results suggest that when individual layer thickness (h) is larger than 5-10 nm, the hardness/strength of three different multilayer systems has the similar length scale effect with decreasing layer thickness, while when h ≤ 5 nm, the three multilayer systems show remarkably different plastic deformation behaviors. The strength curves exhibit the variation trends of unchanging, softening and increasing corresponding to Cu/Ta, Ag/Cu and Ag/Nb multilayers, respectively. The microstructure analysis shows that three kinds of multilayers have totally different interfacial structures, which lead to the different strengthening or softening mechanisms.

关键词: Metallic , multilayers , Plastic , deformation , Interfacial , structures , Strengthening , mechanism

SYNTHESIS AND MICROSTRUCTURE OF SUPERHARD TiN/SiNx MULTILAYER THIN FILMS

M.P.LeBlanc

金属学报(英文版)

Multilayer thin films of TiN/SiNx have been deposited onto heated Si 100 substrates (200℃) by reactive dc-magnetron sputtering from Ti and Si targets in an Ar-N2 gas mixture. The rotation speed of the substrate homer was varied from 1 to 20rpm, while target currents were held constunt, to produce bilayer periods varying from approximately 22 to 0.6nm. These multilayer films were characterized by atomic force microscopy (AFM), cross-sectional transmission electron microscopy (TEM), scanning electron microscopy (SEM), and microhardness measurements. TEM and SEM studies showed elimination of columnar structure in TiN, owing to the incorporation of amorphous SiNx layers. The crystallinity of TiN and amorphous nature of SiNx were confirmed by high resolution TEM. An optimum rotation speed was observed, at which hardness was a maximum. The resulting bilayer period was found to be approximately 1.6nm, which resulted in a significant improvement in microhardness (-57GPa). The rms surface roughness for this film was less than 1.5nm.

关键词: multilayers , null , null

Tb(P2Mo17O61)2/PAMAM纳米复合膜的制备及荧光性质研究

张晓凤 , 何晓蕾 , 黄晓灵 , 黄秋锋 , 林深

功能材料 doi:10.3969/j.issn.1001-9731.2014.06.010

利用层接层自组装法技术,制备了“稀土多金属氧酸盐/聚酰胺-胺树形分子”无机/有机纳米荧光薄膜[Tb(P2Mo17O61)2/PAMAM]n,利用紫外-可见光谱(UV-Vis)、X 射线光电子能谱(XPS)、原子力显微镜(AFM)、荧光光谱对所制备的薄膜进行了组成、结构和性能的表征。研究结果表明,无机和有机组分通过静电作用成膜,复合膜的增长是线性均一、层层增长的过程,复合膜表面是由粒径较为均匀的球状粒子分布而成。与固体 Tb(P2Mo17O61)2相比,复合膜的荧光激发光谱出现了一宽的配体-金属电荷跃迁峰,发射光谱不但体现了稀土元素 Tb3+的特征发射,且 Tb3+劈裂出一新的发射峰,新峰的出现是由于 Tb3+所处的晶体场的对称性减弱引起的。

关键词: 层层自组装 , 多金属氧酸盐 , 聚酰胺-胺 , 多层复合膜 , 荧光

MgB2/Ta多层膜的制备及性质

周章渝 , 侯雪 , 杨晓玲 , 陈会 , 王松 , 卢海秋 , 肖植芬 , 傅兴华

低温物理学报

本文应用磁控溅射技术(MS)和混合物理化学气相沉积法(HPCVD)在单晶Al2 O3基底上制备MgB2/Ta多层膜.通过扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线衍射(XRD)和标准四线法对MgB2/Ta试样的表面形貌、晶体结构、超导特性及断面结构进行了测量研究.结果表明MgB2/Ta多层膜结构清晰,超导薄膜显示出良好的超导特性.

关键词: MgB2超导薄膜 , 钽薄膜 , 多层膜 , 混合物理化学气相沉积法 , 磁控溅射技术

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