A5072405179- Additive Manufacturing Materials and Processes
- Welding Techniques and Residual Stresses
- Additive Manufacturing and 3D Printing Technologies
- Advanced Semiconductor Detectors and Materials
- nanoparticles nucleation surface interactions
- Laser-induced spectroscopy and plasma
- Manufacturing Process and Optimization
- Ion channel regulation and function
- Heat Transfer and Optimization
- Adhesion, Friction, and Surface Interactions
- Advanced Chemical Sensor Technologies
- Electron and X-Ray Spectroscopy Techniques
- Model Reduction and Neural Networks
- Laser Material Processing Techniques
- Calibration and Measurement Techniques
- Neuroscience and Neural Engineering
- Cellular Mechanics and Interactions
- Reliability and Agreement in Measurement
- Nasal Surgery and Airway Studies
- Inhalation and Respiratory Drug Delivery
- Nanotechnology research and applications
- Polymer Nanocomposite Synthesis and Irradiation
- Clinical Laboratory Practices and Quality Control
- Advanced Surface Polishing Techniques
- Thermography and Photoacoustic Techniques
Northwestern University
2019-2024
National Institute of Standards and Technology
2023
Wright-Patterson Air Force Base
2017
University of Rhode Island
1998
Occidental Petroleum (United States)
1980
A novel method to measure cooling rates during solidification in Directed Energy Deposition (DED) using on-axis photodiode-based Planck thermometry (PDPT) was developed. The proposed can monitor the average in-situ melt pool temperature at a 100 kHz acquisition rate. This is much faster than other thermal imaging methods, such as an IR (50∼200 Hz) or camera (25∼100 Hz), due use of photodiode single-pixel measurements. PDPT measures by detecting two visible wavelengths from coaxial, top-down...
Abstract Process defects currently limit the use of metal additive manufacturing (AM) components in industries due to shorter fatigue life, potential for catastrophic failure, and lower strength. Conditions under which these form, their mechanisms, are starting be analyzed improve reliability structural integrity highly customized parts. We situ, high-speed X-ray imaging conjunction with a high throughput laser, powder-blown directed energy deposition setup observe powder particle impact...
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Porosity continues to be a concern for the performance of additively manufactured parts. One source porosity is powder-borne porosity—porosity that contained in powder itself. To create fully dense part, these pores need released from melt pool. This study utilizes an in-situ x-ray imaging technique elucidate underlying physical phenomena driving capture or escape directed energy deposition (DED). In total, 80 instances were captured pool identified and tracked. Ultimately, six mechanisms...
While directed energy deposition (DED) can provide tremendous flexibility in both geometry and materials, there are still many challenges that need to be overcome before this technology freely used industry 1 .Previous work has established a link between the shape of pores cooling rate 2 , however, more fundamental understanding process needs fully established.Highspeed synchrotron imaging adequate spatial temporal resolutions capture critical phenomena such as melt pool dynamics, powder...
ABSTRACT In this study, the deposition of particles (0.3 μm to 2.5 in diameter) within a silicone rubber model human upper respiratory system was studied. The domain tract under investigation begins at entrance (nostrils and mouth) continues through second generation tracheobronchial airways (main bronchi). particle efficiency sample computed by measuring concentration inlet outlet model. regional patterns fluorescent 0.7 examined intensity with fluorescence spectrophotometer. For simulated...
Laser metal additive manufacturing has become an increasingly popular technology due to its flexibility in geometry and materials. As one of the commercialized processes, powder-blown directed energy deposition (DED) been used multiple industries, such as aerospace, automotive, medical device. However, a lack fundamental understanding remains for this process, many opportunities alloy development implementation can be identified. A high-throughput, situ DED system capable multi-layer builds...
Abstract Laser polishing (LP) provides a fast and efficient way of remelting part surfaces manufactured by additive manufacturing to alter both their geometric as well physical properties. Depending on the laser parameters, remelted with different properties are achieved, majority exhibiting lower surface roughness compared original surface. In this study, high-power continuous fiber is used polish Inconel 718 (IN718) produced depositing single layer clads steel substrate powder-blown...
Metal additive manufacturing has become an increasingly popular technology and receives interest from multiple business sectors that require optimally lightweight components mass customization (aerospace, automotive, medical device). Directed energy deposition (DED) is one of the main laser-based processes, but a fundamental understanding process lacking partly because it not been focus highspeed, in-situ x-ray imaging studies like laser powder bed fusion has. A novel DED system presented...
Abstract The process parameters of Directed Energy Deposition (DED) have been widely studied including laser power, powder flow rate, and scanning speed. These affect clad dimension melt pool temperature, which are directly related to part quality. However, laser/powder profiles their alignment obtained less attention due the cumbersome characterization process, although they can be associated with local energy density for formation. This study examines impact between beam distributions in...
Particle counting using Coulter counters is normally practiced at low rates to avoid interference due coincidence effects. For the purpose of measuring mean and its variation, it shown that much higher than recommended can be safely used without compromising precision.