A5059264162- Metallurgy and Material Forming
- Microstructure and mechanical properties
- Additive Manufacturing Materials and Processes
- Microstructure and Mechanical Properties of Steels
- Aluminum Alloy Microstructure Properties
- Solidification and crystal growth phenomena
- Electron and X-Ray Spectroscopy Techniques
- Metal Forming Simulation Techniques
- Additive Manufacturing and 3D Printing Technologies
- Advanced Materials Characterization Techniques
- Manufacturing Process and Optimization
- Advanced Electron Microscopy Techniques and Applications
- Metal and Thin Film Mechanics
- Advanced Welding Techniques Analysis
- Welding Techniques and Residual Stresses
- High Temperature Alloys and Creep
- Hydrogen embrittlement and corrosion behaviors in metals
- Metallurgical Processes and Thermodynamics
- Advanced Battery Technologies Research
- nanoparticles nucleation surface interactions
- Advanced X-ray Imaging Techniques
- Advanced Surface Polishing Techniques
- Machine Learning in Materials Science
- Titanium Alloys Microstructure and Properties
- Magnetic Properties and Applications
United States Naval Research Laboratory
2015-2024
Naval Research Laboratory Materials Science and Technology Division
2006-2014
United States Navy
2007-2012
Northwestern University
2000-2006
National Health Council
2006
National Academies of Sciences, Engineering, and Medicine
2006
University of Minnesota
1999-2001
This work combines experiments and computer models in order to understand the relationships between electrode microstructure ionic transport resistances so that one may predict cell performance from fundamental principles. A scanning electron microscope (SEM) with focused ion beam (FIB) was used image sections of commercially made porous electrodes utilizing LiCoO2 active material. The images reveal existence discrete carbon domains microstructure. Further indicated these are highly tortuous...
Most metals, ceramics, semiconductors and rocks are composed of small crystals known as grains. When annealed, this polycrystalline structure coarsens, thus allowing the properties a material to be tailored for particular application. The mobility grain boundaries is thought determined by crystallography adjacent crystals, but experimental validation in bulk materials lacking. Here we developed novel fitting methodology direct comparison time-resolved three-dimensional data simulations...
Means for assessing the nonlinear optical properties of nanoscale materials are key importance advancement active nanophotonics. By correlating second-harmonic generation (SHG) with electron backscattered diffraction from single GaN nanowires (NWs), we demonstrate that far-field microscopic imaging SHG offers an approach distinguishing crystallographic orientations NWs lying on a substrate. The quasi-static approximation, which should prove useful in describing many nanophotonic behaviors,...
In materials science the orientation of a crystal lattice is described by means rotation relative to an external reference frame. A number representations are in use, including Euler angles, matrices, unit quaternions, Rodrigues–Frank vectors and homochoric vectors. Each representation has distinct advantages disadvantages with respect ease use for calculations data visualization. It therefore convenient be able easily convert from one another. However, historically, each been implemented...
Abstract The Additive Manufacturing Benchmark Test Series (AM Bench) provides rigorous measurement data for validating additive manufacturing (AM) simulations a broad range of AM technologies and material systems. Bench includes extensive in situ ex measurements, simulation challenges the modeling community, corresponding conference series. In 2022, second round challenge problems, were completed, focusing primarily upon laser powder bed fusion (LPBF) processing metals, both extrusion vat...
The experimental measurement of the evolution interfaces in three dimensions is reviewed, concentrating on polycrystalline and solid-liquid systems, including growth coarsening dendritic systems during liquid-phase sintering. Both ex situ destructive techniques nondestructive are considered. importance making three-dimensional measurements that can be quantified unambiguously compared with theory discussed, showing these provide a direct validation critical initial conditions for simulations.
Abstract The crystallographic textures produced during additive manufacturing can be understood, predicted, and manipulated by varying the grain nucleation growth processes. resultant are primarily dictated melt pool geometry, which defines local thermal gradient thus preferred crystal directions, as well scan strategy, controls propagation of orientations into subsequent layers. This texture diluted through heterogeneous new orientations, occur a variety mechanisms. ability to control...
A simplified electrochemical etching technique has been developed to produce conical tungsten tips with radii of curvature ranging between 0.05 and 3 μm. These were characterized using scanning electron microscopy. Following characterization, the mounted into tip holders used in nanoindentation experiments on bulk aluminum, polystyrene, polyethylene samples. Calculated modulus values for polymers, based upon indentation data known radii, agreed very well obtained more macroscopic techniques...