Speker: DAVID KINDERLEHRER
Center for Nonlinear Analysis and Department of Mathematical Sciences, Carnegie Mellon University, Pittsburgh, PA

Title: Interfaces in polycrystals

Abstract: Most technologically useful materials are polycrystalline, comprised  
of many small grains separated by interfaces, called grain  
boundaries. The energetics and connectivity of this network of  
interfaces plays a role in many material properties and across many  
scales of use. Preparing arrangements of grains and boundaries, a  
texture, suitable for a given purpose is a central problem in  
materials science.  Recent years have witnessed a changing paradigm  
in experimental science:  automated data acquisition technologies,  
now practiced in disciplines as varied as materials science and  
molecular biology, allow vast interrogation at certain scales.  
Typically most interesting are those mesoscales rich in information.  
The yield has been huge amounts of data being collected in many  
scientific disciplines, demanding novel approaches for  
interpretation. These advances pose new challenges for our  
understanding of such systems through mathematical modeling,  
simulation, and analysis.

What does this have to do with polycrystals?  A material leaves an  
encoded 'footprint' in its microscopic image.  We have discovered the  
key to the code.  It offers a new paradigm for grain growth.

This is a discussion of work done in the CMU MRSEC whose first  
director was Brent Adams, now at BYU.  Collaborators include K.  
Barmak, G. Rohrer, A. Rollett, and S. Ta'asan (faculty) and I.  
Livshits, J. Lee, M. Emelianenko, E. Eggeling, P. Yu, and G. Leiva  
(postdocs and students).