Highly reactive energetic films by pre-stressing nano-aluminum particles

Date
2019-12-09
Authors
Bello, Michael
Williams, Alan
Levitas, Valery
Tamura, Nobumichi
Levitas, Valery
Unruh, Daniel
Warzywoda, Juliusz
Pantoya, Michelle
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Aerospace Engineering
Organizational Unit
Ames Laboratory
Organizational Unit
Mechanical Engineering
Organizational Unit
Journal Issue
Series
Department
Aerospace EngineeringAmes LaboratoryMechanical Engineering
Abstract

Energetic films were synthesized using stress altered nano-aluminum particles (nAl). The nAl powder was pre-stressed to examine how modified mechanical properties of the fuel particles influenced film reactivity. Pre-stressing conditions varied by quenching rate. Slow and rapid quenching rates induced elevated dilatational strain within the nAl particles that was measured using synchrotron X-ray diffraction (XRD). An analytical model for stress and strain in a nAl core–Al2O3 shell particle that includes creep in the shell and delamination at the core–shell boundary, was developed and used for interpretation of strain measurements. Results show rapid quenching induced 81% delamination at the particle core–shell interface also observed with Transmission Electron Microscopy (TEM). Slower quenching elevated dilatational strain without delamination. All films were prepared at approximately a 75:25 Al:poly(vinylidene fluoride) PVDF weight ratio and were 1 mm thick. A drop weight impact test was performed to assess ignition sensitivity and combustion. Stress altered nAl exhibited greater energy release rates and more complete combustion than untreated nAl, but reaction dynamics and kinetics proceeded in two different ways depending on the nAl quenching rate during pre-stressing.

Comments

This article is published as Bello, Michael N., Alan M. Williams, Valery I. Levitas, Nobumichi Tamura, Daniel K. Unruh, Juliusz Warzywoda, and Michelle L. Pantoya. "Highly reactive energetic films by pre-stressing nano-aluminum particles." RSC Advances 9, no. 69 (2019): 40607-40617. DOI: 10.1039/C9RA04871E. Posted with permission.

Description
Keywords
Citation
DOI
Collections