Materials in 3D: New Tomography Approaches and Applications to High Temperature Materials

Featuring Tresa Pollock, Ph.D.

Alcoa Professor, Department of Materials

University of California, Santa Barbara



Abstract:



Tomographic imaging has led to new insights on the structure and behavior of a wide range of biological, geological and physical systems.  A major challenge for tomography of engineering materials is the level of resolution required and physical size of the 3-D datasets required. Fluid flow and the permeability of a 3-D dendritic structure during growth of nickel-base single crystals is an example of a high temperature materials problem that requires large, 3-D datasets.   A new tomography technique that utilizes the unique characteristics of femtosecond laser ablation for rapid serial sectioning and assembly of mm3-scale 3-D datasets will be presented. The femtosecond laser can machine large volumes of material due to the high focused beam intensities (>1018 W/cm2), high laser repetition rate in the kHz range, and ultrashort femtosecond (10-15 s) laser pulses with very limited collateral damage. Some examples of the application of this new technique will be presented for systems with very low volume fractions of micron-scale particles. Future directions for femtosecond laser-assisted tomography will be discussed.



About the Speaker:



Tresa Pollock, Ph.D., is the Alcoa Professor of Materials at the University of California, Santa Barbara.  She graduated with a B.S. degree from Purdue University in 1984, and a Ph.D. degree from MIT in 1989.  Pollock was employed at General Electric Aircraft Engines from 1989 to 1991.  She was a professor at Carnegie Mellon University from 1991 to 1999, and the University of Michigan from 2000 - 2010.  Her current research focuses on the processing and properties of structural materials and coatings and on the use of ultrafast lasers for microfabrication and materials diagnostics.  She was elected to the U.S. National Academy of Engineering in 2005, is a Fellow of TMS and ASM International, associate editor of Metallurgical and Materials Transactions and was the 2005-2006 President of The Minerals, Metals and Materials Society.