# University of Minnesota

Aerospace Engineering and Mechanics

**Fall 2000 Seminar Series**

*The
Dynamics of Ostwald Ripening in Elastically Stressed Solids*

*Abstract*

Phase separation in crystalline solids is
almost always accompanied by long ranged elastic stress. These stresses, which
result from a difference in lattice parameter between the particle and matrix
can give rise to qualitatively new phenomena as compared those in a stress-free
system, such as changes in particle shape with increasing particle size,
particle migration and alignment, and inverse coarsening wherein small
particles grow at the expense of large particles. At issue is the manner in
which these local phenomena influence the dynamics of ensemble-averaged
quantities. We have investigated the dynamics of Ostwald ripening in
elastically stressed crystalline solids through large-scale numerical
simulations. Using the insight provided by the simulations, a theory for the
dynamics of late-stage phase separation in elastically anisotropic homogeneous
solids is developed. Both the theory and simulations show that for the systems
considered elastic stress does not alter the exponent of the temporal power law
for the average particle size but does effect the amplitude of the power law in
a manner that is only a function of the symmetry of the particle morphology.
The effect of interparticle elastic interactions on particle morphology and
spatial correlations will also be discussed.

### Friday,
December 8, 2000

209 Akerman
Hall

2:30-3:30 p.m.

### Refreshments served after the seminar in
227 Akerman Hall.

Disability accomodations provided upon request.

Contact Kristal Belisle, at (612)
625-8000.