Experimental Mechanics

, Volume 50, Issue 1, pp 117–123 | Cite as

Strain Mapping of Al–Mg Alloy with Multi-scale Grain Structure using Digital Image Correlation Method

Article

Abstract

Al–Mg alloy powder was mechanically milled in liquid N2 (cryomilling) to produce thermally stable powder with nanocrystalline (NC) microstructure for the manufacture of high-strength alloys. A multi-scale microstructure was achieved by blending unmilled coarse-grained (CG) powder with cryomilled powder and subsequently consolidating. The final bulk alloy was comprised of ultra-fine grained (UFG) regions and discrete CG bands. Dynamic observations of tensile deformation of the alloy were recorded using a micro-straining module attached to a light microscope, and the displacements were measured by digital image correlation (DIC). Strain inhomogeneity between UFG regions and ductile CG bands was observed in the micro-strain (strain order of 10−4–10−6) range, and the strain behavior was interpreted in terms of dislocation plasticity. Special emphasis was given to the distinct displacements between adjoining regions during deformation.

Keywords

Digital image correlation Strain mapping Strain localization Cryomilling Ultrafine grains Bimodal grain structures 

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Copyright information

© Society for Experimental Mechanics 2009

Authors and Affiliations

  1. 1.Department of Chemical Engineering and Materials ScienceUniversity of Southern CaliforniaLos AngelesUSA

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