Prof. Andrew Minor

New modes of imaging for in situ TEM nanomechanical testing

Affiliation: 1 Department of Materials Science & Engineering, University of California, Berkeley, and National
Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory

Abstract

This talk will highlight recent advances with in situ Transmission
Electron Microscopy (TEM) nanomechanical testing techniques that provide
insight into small-scale plasticity and the evolution of defect structures in
materials. In addition to measuring the strength of small-volumes, measuring
the evolution of strain during plastic deformation is of great importance for
correlating the defect structure with material properties. Here we demonstrate
that strain mapping can be carried out during in-situ deformation in a TEM
with the precision of a few nanometers without stopping the experiment. Our
method of local strain mapping consists of recording large multidimensional data
sets of nanodiffraction patterns using a high-speed direct electron detector (4D-
STEM). This dataset can then be reconstructed to form a time-dependent local
strain-map with sufficient resolution to measure the transient strains occurring
around individual moving dislocations. This talk will describe our recent results
from in situ TEM nanomechanical testing that provide insight into multiscale
metallurgical phenomena using these techniques.

Bio

Andrew Minor is a Professor at the University of California, Berkeley in the
Department of Materials Science and Engineering and also holds a joint
appointment at the Lawrence Berkeley National Laboratory where he is the
Facility Director of the National Center for Electron Microscopy in the Molecular
Foundry. He received a B.A. in Economics and Mechanical Engineering from
Yale University and his MS and Ph.D. in Materials Science and Engineering from
U.C. Berkeley. He has co-authored over 175 publications and presented over
100 invited talks on topics such as nanomechanics, lightweight alloy
development, characterization of soft materials and in situ TEM technique
development. His honors include the LBL Materials Science Division Outstanding
Performance Award (2006 & 2010), the AIME Robert Lansing Hardy Award from
TMS (2012) and the Burton Medal from the Microscopy Society of America
(2015).