Mechanical behavior of nano scale Cu/PdSi multilayers
Mechanical behavior of nano scale Cu/PdSi multilayers
复制标题
DOI：
10.1016/j.actamat.2013.04.047
复制
发表时间：
2013-08-01
期刊：
影响因子：
9.4
通讯作者：
Volkert, C. A.
中科院分区：
文献类型：
--
作者：
Knorr, I.;Cordero, N. M.;Volkert, C. A.
Berkovich纳米压痕和单轴微压缩测试已经进行了化学气相沉积的结晶Cu/非晶Pd 0.77Si 0.23多层膜与单个层的厚度范围从10到120 nm。弹性模量，强度和变形形态进行了比较，所有样品，以确定层厚度和体积分数的趋势。多层膜具有2GPa量级的强度，由此可以推断2GPa量级的Cu层强度。高强度归因于通过抑制晶体/非晶界面处的位错湮灭或传输在多晶Cu层中的非常高的应变硬化。横截面显微镜显示均匀的变形层内，在界面处的分层的情况下，和折叠和旋转的层，形成层间剪切带。剪切带形成的剪切应力平行于界面，并涉及拉伸塑性应变高达85%，而不破裂的层。均匀变形和高应变失效归因于非晶和多晶层之间的载荷分担和层内应变局部化的抑制。(C)2013 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Berkovich nanoindentation and uniaxial microcompression tests have been performed on sputter-deposited crystalline Cu/amorphous Pd0.77Si0.23 multilayered films with individual layer thicknesses ranging from 10 to 120 nm. Elastic moduli, strengths and deformation morphologies have been compared for all samples to identify trends with layer thicknesses and volume fractions. The multilayer films have strengths on the order of 2 GPa, from which Cu layer strengths on the order of 2 GPa can be inferred. The high strength is attributed to extraordinarily high strain hardening in the polycrystalline Cu layers through the inhibition of dislocation annihilation or transmission at the crystalline/amorphous interfaces. Cross-sectional microscopy shows uniform deformation within the layers, the absence of delamination at the interfaces, and folding and rotation of layers to form interlayer shear bands. Shear bands form where shear stresses are present parallel to the interfaces and involve tensile plastic strains as large as 85% without rupture of the layers. The homogeneous defoimation and high strains to failure are attributed to load sharing between the amorphous and polycrystalline layers and the inhibition of strain localization within the layers. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.