THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING

GEORGIA INSTITUTE OF TECHNOLOGY

Under the provisions of the regulations for the degree

DOCTOR OF PHILOSOPHY

on Tuesday, April 10, 2018

10:00 AM
in MRDC 3515

will be held the

DISSERTATION PROPOSAL DEFENSE

for

Yung Suk "Jeremy" Yoo

“Effects of constituent particles and dispersoids on heterogeneous deformation of AA 6XXX alloys”

Committee Members:

Prof. Josh Kacher, Advisor, MSE

Prof. Christopher Muhlstein, MSE

Prof. Richard Neu, MSE

Prof. Olivier Pierron, ME

Dr. Sazol Das, Novelis Inc.

Abstract:

Aluminum alloys are becoming more important as the world strives for more environmentally friendly and fuel-efficient products. For example, the aviation and automotive industries capitalize on aluminum’s high strength-to-weight ratio to manufacture lighter and therefore more efficient aircrafts and vehicles. Aluminum’s versatility stems from being compatible with a wide variety of alloying elements and heat treatments that can tailor these properties to meet the service requirements. Naturally, these alloys will have complex microstructures that will deform heterogeneously under different loading conditions. To safely incorporate aluminum alloys into these products, it is imperative to understand how secondary phases influence how damage accumulates in the material and lead to ductile failure.

This research will use electron microscopy techniques to understand the effects of constituent particles and dispersoids on the deformation behavior of AA 6061 and 6451. This study will employ multiscale electron microscopy techniques ranging from mesoscale in-situ EBSD and DIC to microscale site-specific high angular resolution EBSD (HREBSD) and TEM. The effects of different secondary phase particles on the strain localization and dislocation accumulation behavior will be quantified using mesoscale EBSD data and DIC. Ultimately, this study will elucidate how these localized damage buildup initiates ductile failure in AA 6XXX alloys.