MSE Seminar - Professor Tresa Pollock - University of California, Santa Barbara
Materials in 3D: Acquiring Information at the Mesoscale via TriBeam Tomography
The development of high fidelity material property and life prediction models, one of the major goals of the National Materials Genome Initiative, often requires three-dimensional information on the distribution of phases, grains or extrinsic defects across a broad range of materials systems. Acquisition of this information in appropriate representative volume elements ultimately limits the use of conventional tomography techniques. A new approach to rapid generation of mesoscale datasets with multiple channels of high-resolution information will be presented. Femtosecond lasers, employed for layer-by-layer ablation, provide these new tomography capabilities. The high pulse frequency (1 kHz) of ultra-short (150 fs) laser pulses can induce material ablation with virtually no thermal damage to the surrounding area; basic experiments on beam-material interactions will be presented. Laser-based tomography has been demonstrated ex-situ with optical imaging and more recently in-situ with a “TriBeam” approach that combines the femtosecond laser with focused ion and electron beams to permit high resolution imaging, as well as crystallographic and elemental analysis. Datasets approaching mm3volumes on a spectrum of metallic, polymer and ceramic systems will be presented. Challenges in analyzing and integrating 3-D datasets with material property and lifing models will be discussed along with future capabilities for this technique.
Tresa Pollock is the Alcoa Professor of Materials and Department Chair at the University of California, Santa Barbara. She graduated with a B.S. from Purdue University in 1984, and a Ph.D. from MIT in 1989. Dr. Pollock was employed at General Electric Aircraft Engines from 1989 to 1991, where she conducted research and development on high temperature alloys for aircraft turbine engines. She was a professor in the Department of Materials Science and Engineering 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. Professor Pollock 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.
Host: Naresh Thadhani
Reception at 3:30 preceeding seminar outside Van Leer Auditorium