Please consider attending the following:

 

MATERIALS ENGINEERING

SEMINAR

 

“Deformation Twinning in Nanocrystalline Al”

 

 

 

By

Yifan Zhang

Purdue MSE Ph.D. Preliminary Exam

 

Advisor: Professor Xinghang Zhang

 

 

 

ABSTRACT

 

 

 

Deformation twinning is one of the major deformation mechanisms in metallic materials to accommodate shear strain and plastic deformation. As widely accepted, Al rarely deforms via deformation twinning because of its high stacking fault energy (142-165 mJ/m2). Only under certain conditions, such as cryogenic temperature, extremely high strain rate, addition of solutes as well as nanoscale grain size, can deformation twins form in Al. Experimental studies and molecular dynamic simulations have revealed the important roles of grain boundaries on the deformation twinning in nanocrystalline (NC)Al. Several GB-mediated twinning mechanisms will be discussed in this work.

 

 

 

 

 

 

Date: Monday, November 6, 2017

Time: 11:30 A.M.

Place: ARMS B071