Quantitative Nanomechanical Testing in a TEM

Dr. Andrew Minor
Department of Materials Science and Engineering,
University of California, Berkeley

Recent  progress  in  both  in  situ  and  ex  situ  small-scale mechanical testing methods has greatly improved our understanding of mechanical  size  effects  in  volumes  from  a  few  nanometers  to  a  few microns.   Besides the important results related to the effect of size on the strength  of  small  structures,  the  ability  to  systematically  measure  the mechanical  properties  of  small  volumes  through  mechanical  probing allows us to test samples that cannot easily be processed in bulk form, such  as  a  specific  grain  boundary  or  a  single  crystal.  In  the  case  of individual  nanostructures,  the  need  to  address  the  nanostructure  in  a direct manner is even more acute, and in situ TEM in many cases makes this  possible.  This  talk  will  describe  our  recent  results  from  in  situ compression  and  tensile  testing  of  metals  to  illuminate  the  origin  of size-dependent  yield  strength  behavior  and  fundamental  deformation structures  in  nanoscale  samples.    In  addition,  comparing  in  situ compression and tensile testing has led to some interesting observations regarding  the  evolution  of  flow  strength  in  nanoscale  samples  during testing.

Andrew  Minor  is  an  Associate  Professor  in  the  Department  of Materials Science and Engineering at University of California, Berkeley. Minor received a B.A. in  Mechanical  Engineering  and Economics from Yale  University,  and  a  M.S.  and  Ph.D.  in  Materials  Science  and Engineering from UC Berkeley. He also holds a joint appointment as a Faculty Scientist at the National Center for Electron Microscopy, at the Lawrence  Berkeley  National  Laboratory.  His  research  group  uses  advanced  electron  microscopy-based  materials  characterization  to investigate  both  organic  and  inorganic  materials.  They  focus  on nanomechanical size effects, characterization of soft materials, and novel in-situ TEM methods for materials science research.