A5023033879- Additive Manufacturing Materials and Processes
- Additive Manufacturing and 3D Printing Technologies
- Welding Techniques and Residual Stresses
- Manufacturing Process and Optimization
- Nanowire Synthesis and Applications
- Titanium Alloys Microstructure and Properties
- Machine Learning in Materials Science
- Simulation Techniques and Applications
- Fluid Dynamics and Thin Films
- High Entropy Alloys Studies
- Vehicle Dynamics and Control Systems
- nanoparticles nucleation surface interactions
- Advanced X-ray and CT Imaging
- Solidification and crystal growth phenomena
- Advanced Materials Characterization Techniques
- Advancements in Semiconductor Devices and Circuit Design
- Industrial Vision Systems and Defect Detection
- Electron and X-Ray Spectroscopy Techniques
- Thermal properties of materials
- Gaussian Processes and Bayesian Inference
- Technology Assessment and Management
- Force Microscopy Techniques and Applications
- Robot Manipulation and Learning
- Calibration and Measurement Techniques
- High Temperature Alloys and Creep
Wright-Patterson Air Force Base
2018-2024
United States Air Force Research Laboratory
2017-2024
Base Materials (United Kingdom)
2021
Northwestern University
2008-2018
National Institute of Standards and Technology
2012-2013
Material Measurement Laboratory
2012-2013
Circumventing spatter Laser powder bed fusion is an additive manufacturing technique that laser-melts layer by to build a three-dimensional (3D) part. Khairallah et al. used experiments and multiphysics model determine the origin of melt defect formation degrade properties built parts (see Perspective Polonsky Pollock). Informed modulation laser power important avoid disturbing creating shadowing. This reduces pore formations leads more uniform 3D-printed parts. Science , this issue p. 660 ;...
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 vapor–liquid–solid (VLS) process of semiconductor nanowire growth is an attractive approach to low-dimensional materials and heterostructures because it provides a mechanism modulate, in situ, composition doping, but the ultimate limits on doping control are ultimately dictated by itself. Under widely used conditions for chemical vapor deposition Si Ge nanowires from Au catalyst droplet, we find that dopants incorporated liquid not uniformly distributed. Specifically, atom probe...
Phase diagrams accounting for capillarity and surface stress in VLS-grown nanowires have been calculated, linearized forms the compositions of solid liquid are given. The solid-vapor interfacial energy causes a significant depression liquidus, impurity concentration wire decreases with decreasing diameter. Nucleation calculations give upper bounds on nucleation temperature supersaturation during growth that consistent measurements Au-Ge system.
Phase-field crystal (PFC) models are able to resolve atomic length scale features of materials during temporal evolution over diffusive time scales. Traditional PFC contain solid and liquid phases, however many important processing phenomena involve a vapor phase as well. In this work, we add an existing model show realistic interfacial near the triple point temperature. For example, exhibits density oscillations at liquid-vapor interfaces that compare favorably data available for in...
This paper presents methods for combining process monitoring, thermal modelling and microstructure characterization together to draw process-to-structure relationships in metal additive manufacturing. The discusses heterogeneities the local processing conditions within additively manufactured components how they affect resulting material structure. Methods registering fusing disparate data sources are presented, some effort is made discuss utility of different specific microstructural...
Neutron spectroscopy experiments show differences in the dynamics at atomic level and phase behavior between saturated DMPC unsaturated DOPC, owing to constraints imposed by double bond latter.
Integrated computational materials engineering (ICME) combines the utility and efficiency of simulations with experimentation to drive forward design discovery. These physics-based data-driven frameworks have enabled material advancement by querying complex process–structure–property–performance relationships inform guide experiments for cost-effective alloy systems. In this study, a proven framework is presented applied towards tailored additively manufactured (AM) high-temperature NiTiHf...
The Vapor-Liquid-Solid method is one of the most popular techniques for growing semiconducting nanowires, and stability liquid droplet an important factor controlling wire morphology and, ultimately, functionality. Earlier theoretical work on axisymmetric systems indicates that lowest-energy configuration varies with surface energies, radius, fluid volume. We test these predictions a fully dynamic phase-field model incorporates viscous flow. Under conditions predicted by this earlier work,...
The desire for increased performance and functionality has introduced additional complexities to the design fabrication of additively manufactured (AM) parts. However, addressing these needs would require improved control over local properties using in-line feedback from fast-acting low-fidelity models during process. In this regard, differential evaporation is an inherent characteristic in metal AM processes, directly influencing chemistry, material properties, functionality, performance....
The ability to dope semiconductor nanowires during growth is an important step toward making functional devices. We develop a model for steady state vapor-liquid-solid of ternary semiconductor-catalyst-dopant nanowire. Our analysis shows that the relative flux dopant atoms through liquid controls mole fraction in solid wire, and local equilibrium constrains catalyst composition compositions liquid. find phase diagram can be used determine upper limit on solid.