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Becker, Michael F.

Publications and source records attributed to Becker, Michael F..

4 records
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DOE OSTI2024

Machine Learning Enabled Atomistic Study of the Micro-Cold Spray Process [Poster]

Micro-cold spray is typically conducted by impacting 200-2000 nm particles at velocities of ~500 m/s. Molecular dynamics simulations have been used to study micro cold spray, but the particles that can be simulated using conventional potentials are much smaller than those used experimentally. The viewgraphs taken from molecular dynamics simulations and shown below are cross-sections of a 50 nm Ta particle with a 3 nm oxide layer impacting at 500 m/s using a machine learning enabled DeePMD potential. Using more expensive reactive interatomic potentials, the previous largest particle size for a metal/oxide impact simulation was 12 nm.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2024

Nanoparticle Impact 2023 Report

Micro-cold spray (MCS) is a thermal spray process that can be used to apply thick ceramic films (1-100 μm) using kinetic energy to consolidate aerosolized powders into a dense film. While this process is compatible with many substrates due to the low working temperatures, the fundamental mechanisms that enable MCS and shape the operational window are poorly understood.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

A strain density function to analyze particle size effects during high velocity impacts of yttria

Here, the impact behavior of a single yttria (Y 2 O 3 ) nanoparticle onto a Y 2 O 3 substrate is studied as a function of particle velocity (300–1200 m/s) and diameter (12–50 nm) using molecular dynamics simulations. To analyze the results, a strain density function is developed to provide both quantitative and qualitative information about the deformation mechanisms that contribute to the final state of the system. This function provides both clear evidence of shear localization and insight into the conditions for which localization occurs during the impact of Y 2 O 3 particles as they approach experimentally relevant sizes. Further analysis shows that localization and fragmentation only occur for Y 2 O 3 impacts with diameters of at least 50 nm, while particles with diameters of 25 nm and smaller deform primarily by amorphization and viscous flow. Implications for the deposition of films of Y 2 O 3 and other rare-earth oxides via the micro cold spray process are discussed.

36 MATERIALS SCIENCE↗