header

Relating Microstructure to Defect Behavior in AA6061 Using a Combined Computational and Multiscale Electron Microscopy Approach

21 Pages Posted: 28 Mar 2019 First Look: Accepted

See all articles by Yung Suk Jeremy Yoo

Yung Suk Jeremy Yoo

Georgia Institute of Technology - School of Materials Science and Engineering

Hojun Lim

Sandia National Laboratories (NM)

John Emery

Sandia National Laboratories (NM)

Josh Kacher

Georgia Institute of Technology - School of Materials Science and Engineering

Abstract

In this study, a multiscale electron microscopy-based approach is applied to understanding how different aspects of the microstructure in a notched AA 6061, including grain boundaries, triple junctions, and intermetallic particles, promote localized dislocation accumulation as a function of applied tensile strain and depth from the sample surface. Experimental measurements and crystal plasticity simulations of dislocation distributions as a function of distance from specified microstructural features both showed preferential dislocation accumulation near intermetallic particles relative to grain boundaries and triple junctions. High resolution electron backscatter diffraction and site-specific transmission electron microscopy characterization showed that high levels of dislocation accumulation near intermetallic particles led to the development of an ultrafine sub-grain microstructure, indicative of a much higher level of local plasticity than predicted from the coarser measurements and simulations. In addition, high resolution measurements in front of a crack tip suggested a compounding influence of intermetallic particles and grain boundaries in dictating crack propagation pathways.

Keywords: Electron microscopy, finite element, ductile fracture, aluminum

Suggested Citation

Yoo, Yung Suk Jeremy and Lim, Hojun and Emery, John and Kacher, Josh, Relating Microstructure to Defect Behavior in AA6061 Using a Combined Computational and Multiscale Electron Microscopy Approach (March 27, 2019). Available at SSRN: https://ssrn.com/abstract=3358892 or http://dx.doi.org/10.2139/ssrn.3358892

Yung Suk Jeremy Yoo (Contact Author)

Georgia Institute of Technology - School of Materials Science and Engineering

Atlanta, GA 30332
United States

Hojun Lim

Sandia National Laboratories (NM)

POB 5800
Albuquerque, NM 87185
United States

John Emery

Sandia National Laboratories (NM)

POB 5800
Albuquerque, NM 87185
United States

Josh Kacher

Georgia Institute of Technology - School of Materials Science and Engineering ( email )

Atlanta, GA 30332
United States

Here is the Coronavirus
related research on SSRN

Paper statistics

Abstract Views
181
Downloads
25