Article ID Journal Published Year Pages File Type
1446819 Acta Materialia 2012 13 Pages PDF
Abstract

The mechanical behavior of incoherent Cu/Zr multilayers was studied in uniaxial compression experiments using micropillars with individual layer thicknesses (h) ranging from 5 to 100 nm. The deformation behavior of these micropillars are size dependent, transiting from dislocation dominated symmetrical slip at large h to shear localization induced by asymmetric slip and grain boundary mediated deformation at small h. During compression studies the multilayer micropillars exhibit a transition from strain hardening to shear softening at small h, and work softening at greater h. A maximum strain hardening rate is observed at a critical h of 20 nm, which was explained in terms of a transition from dislocation interactions to cross-slip of dislocations. The mechanical strength of the micropillars is also dependent on h, which was quantitatively analyzed using the confined layer slip model. In addition, the influence of pillar diameter on the mechanical behavior is also investigated. The effect of extrinsic size on the deformation mechanisms is discussed with respect to the intrinsic size effect with variation in h.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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