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 primary deformation mechanisms in numerous metallic materials to accommodate shear strain and plastic deformation. In general, even under extreme deformation conditions, coarse-grained monolithic Al rarely deforms via deformation twinning because of its high stacking fault energy (104-142 mJ/m2). One practical pathway to facilitate deformation twinning is via grain refinement. Experimental studies and molecular dynamic simulations show several unique deformation twinning mechanisms in nanocrystalline (nc) Al with an average grain size of 100 nm or less. Furthermore, physical models have also been established to describe the nucleation and growth process of deformation twins. Date: Thursday, October 5, 2017 Time: 9:30 A.M. Place: ARMS 1021