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Title: Nanocomposite thermite powders with improved flowability prepared by mechanical milling

Nanocomposite thermite powders can be used in reactive parts and components. Manufacturing these components requires tailoring powder particle size distributions, particle shapes, and powder flowability. Specifically, an improved flowability is desired to use such powders as feedstock in additive manufacturing. Arrested reactive milling (ARM) offers a versatile and practical approach for preparing nanocomposite thermites with fully dense particles, which will retain their structures and mixedness between reactive components while being stored, handled, and processed. However, ARM products usually have broad particle size distributions, rock-like particle shapes, and poor flowability. Here in this study, ARM is modified to include a low-energy milling step to tune the shapes and flowability of the prepared powders. Experiments are performed with aluminum-rich Al·Fe 2O 3 thermites. After the initial nanocomposite thermite is prepared in a planetary mill, it is additionally milled at a reduced rotation rate, replacing milling balls with smaller glass beads, and adding different liquid process control agents. Powders with modified particle shapes and size distributions are obtained, which have substantially improved flowability compared to the initial material. The reactivity of the initial and modified powders is evaluated using their ignition on a heated wire, by electro-static discharge, by thermal analysis (DSC) andmore » in constant volume explosion tests. Finally, the reactivity of the modified powders is not diminished; instead, an improved reactivity is observed for selected samples.« less
Authors:
 [1] ; ORCiD logo [1] ;  [1] ;  [2] ; ORCiD logo [1]
  1. New Jersey Inst. of Technology, Newark, NJ (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Report Number(s):
LLNL-JRNL-736252
Journal ID: ISSN 0032-5910; 886340
Grant/Contract Number:
AC52-07NA27344
Type:
Accepted Manuscript
Journal Name:
Powder Technology
Additional Journal Information:
Journal Volume: 327; Journal Issue: C; Journal ID: ISSN 0032-5910
Publisher:
Elsevier
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 42 ENGINEERING; Feedstock powders; Additive manufacturing Reactive materials; Energetic materials
OSTI Identifier:
1466137

Nguyen, Quang, Huang, Ci, Schoenitz, Mirko, Sullivan, Kyle T., and Dreizin, Edward L.. Nanocomposite thermite powders with improved flowability prepared by mechanical milling. United States: N. p., Web. doi:10.1016/j.powtec.2017.12.082.
Nguyen, Quang, Huang, Ci, Schoenitz, Mirko, Sullivan, Kyle T., & Dreizin, Edward L.. Nanocomposite thermite powders with improved flowability prepared by mechanical milling. United States. doi:10.1016/j.powtec.2017.12.082.
Nguyen, Quang, Huang, Ci, Schoenitz, Mirko, Sullivan, Kyle T., and Dreizin, Edward L.. 2018. "Nanocomposite thermite powders with improved flowability prepared by mechanical milling". United States. doi:10.1016/j.powtec.2017.12.082. https://www.osti.gov/servlets/purl/1466137.
@article{osti_1466137,
title = {Nanocomposite thermite powders with improved flowability prepared by mechanical milling},
author = {Nguyen, Quang and Huang, Ci and Schoenitz, Mirko and Sullivan, Kyle T. and Dreizin, Edward L.},
abstractNote = {Nanocomposite thermite powders can be used in reactive parts and components. Manufacturing these components requires tailoring powder particle size distributions, particle shapes, and powder flowability. Specifically, an improved flowability is desired to use such powders as feedstock in additive manufacturing. Arrested reactive milling (ARM) offers a versatile and practical approach for preparing nanocomposite thermites with fully dense particles, which will retain their structures and mixedness between reactive components while being stored, handled, and processed. However, ARM products usually have broad particle size distributions, rock-like particle shapes, and poor flowability. Here in this study, ARM is modified to include a low-energy milling step to tune the shapes and flowability of the prepared powders. Experiments are performed with aluminum-rich Al·Fe2O3 thermites. After the initial nanocomposite thermite is prepared in a planetary mill, it is additionally milled at a reduced rotation rate, replacing milling balls with smaller glass beads, and adding different liquid process control agents. Powders with modified particle shapes and size distributions are obtained, which have substantially improved flowability compared to the initial material. The reactivity of the initial and modified powders is evaluated using their ignition on a heated wire, by electro-static discharge, by thermal analysis (DSC) and in constant volume explosion tests. Finally, the reactivity of the modified powders is not diminished; instead, an improved reactivity is observed for selected samples.},
doi = {10.1016/j.powtec.2017.12.082},
journal = {Powder Technology},
number = C,
volume = 327,
place = {United States},
year = {2018},
month = {1}
}