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Application of Al-Cu-W-Ta graded density impactors in dynamic ramp compression experiments

Kelly, James P. and Nguyen, Jeffrey H. and Lind, Jonathan and Akin, Minta C. and Fix, Brian J. and Saw, Cheng K. and White, Elida R. and Greene, Waldi O. and Asimow, Paul D. and Haslam, Jeffery J. (2019) Application of Al-Cu-W-Ta graded density impactors in dynamic ramp compression experiments. Journal of Applied Physics, 125 (14). Art. No. 145902. ISSN 0021-8979. https://resolver.caltech.edu/CaltechAUTHORS:20190411-120804967

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Abstract

Graded density impactors (GDIs) are used to dynamically compress materials to extreme conditions. Two modifications to a previously developed Mg-Cu-W GDI are made in this work before using it in a dynamic compression experiment: Mg is replaced with Al and a Ta disk is glued to the back. The Mg phase is replaced by Al because FCC Al remains solid to higher pressure along its Hugoniot compared to Mg. The addition of the Ta disk creates a constant particle velocity regime and facilitates a definition of peak pressure states. Microstructure analysis, profilometry, and ultrasonic C-scans of the Al-Cu-W GDI all confirm excellent uniformity. We evaluated signal variation in the radial direction of a dynamically compressed Al-LiF bilayer target to evaluate the contribution of spatial nonuniformity to errors. Velocity traces from five photon Doppler velocimetry (PDV) probes located at different radial distances from the center of the target varied at most by 1.1% with a root mean square of 0.3% during the compression ramp, demonstrating low PDV measurement error over a relatively large experimental area. The experimental PDV data also agrees well with 1D simulations that use inputs from predictive characterization models developed for the material properties resulting from tape casting, laminating, and powder consolidation processes. Low measurement error during quasi-isentropic compression, leading to better precision, ensures a robust platform to reach extreme compression and low-temperature recovery states and facilitates discovery via synthesis, quenching, and preservation of new high-pressure phases.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1063/1.5055398DOIArticle
ORCID:
AuthorORCID
Akin, Minta C.0000-0001-5742-8663
Asimow, Paul D.0000-0001-6025-8925
Additional Information:© 2019 Author(s). Published under license by AIP Publishing. Submitted: 7 September 2018 · Accepted: 26 March 2019 · Published Online: 11 April 2019 This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. The authors would also like to thank Ernest Bianchi at Maryland Ceramic & Steatite Company, Inc., for tape casting services, Renee Posadas, J. Castellanos, Joshua Ruelas, and Paul Benevento at the Lawrence Livermore National Laboratory for assistance with characterization and fabrication of the impactors, Sharon Torres and James Embree for assistance with metallography, Bob Nafzinger for target fabrication, and Michael J. Burns and Russel Oliver for assistance with the Light Gas Gun experiment. Collaboration with the Caltech Lindhurst Laboratory for Experimental Geophysics is supported by LLNL subcontract B621015.
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-AC52-07NA27344
Lawrence Livermore National LaboratoryB621015
Issue or Number:14
Record Number:CaltechAUTHORS:20190411-120804967
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20190411-120804967
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:94659
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:11 Apr 2019 19:43
Last Modified:04 May 2020 17:32

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