Materials Research Lecture

The development of high fidelity material property and life prediction models often requires three-dimensional information on the distribution of phases, interfaces, grains or extrinsic defects. Acquisition of this information in appropriate representative volume elements ultimately limits the use of conventional tomography techniques.  The use of femtosecond lasers for layer-by-layer ablation provides new tomography capabilities in terms of the volume of material that can be sampled in relatively short time periods.  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.  An in-situ platform for laser-based tomography that combines the femtosecond laser within a focused ion beam platform has been developed.   This TriBeam platform allows for high resolution imaging, as well as crystallographic and elemental analysis on a spectrum of metallic, polymer and ceramic systems.  New 3D mesoscale characterization information critical for optimization of the properties of NiTiSn-based thermoelectrics, Cu-W composites and Ni-based turbine disk alloys will be presented.