Electrophoretic Deposition and Thermo-Chemical Properties of Al/Fe2O3 Nanothermite Thick Films

Jie Wu 1, 2

Songbai Xue 1, Email

Denzel Bridges 2

Yongchao Yu 2

Cary Smith 2

Kunlun Hong 3

Curtis Hill 4

Zhili Zhang 2

Zhili Feng 5

Anming Hu 2, Email

1 College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China

2 Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee Knoxville, 1512 Middle Drive, Knoxville, TN 37996, USA

3 Center of Nanophase Material Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA

4 CK Technologies, 268 Lewis Tate Rd. Meridianville, AL 35759, USA

5 Materials Science and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

Abstract

We have successfully fabricated α-Fe2O3 oxidizers with different shapes, including nanoparticles (NPs, diameter: ~22.1 nm), nanorods 2 3 (NRs, length: 385.3 nm) and nanowires (NWs). For the Al/Fe2O3 NPs thermite reaction, as the nominal weight ratio for Al/Fe2O3 (NPs) 2 3 2 3 reaches 2.5:1, the fastest combustion velocity (2.03 m/s), the largest instant plume propagation speed (10.71 m/s) as well as the maximum heat release (~9.46 kJ/g) can be achieved. However, with the same nominal weight ratio, the average combustion velocity and the instant plume speed of Al/Fe2O3 (NRs) and Al/Fe nitrilotriacetic acid precusors NWs (FeNTA,) nanothermite are only about 0.16 m/s and 4.96 2 3 m/s, and 0.098 m/s and 3.28 m/s, respectively. This is probably due to the shape difference that renders different contact configurations between nano-fuel and nano-oxidizer. In addition, an incomplete calcination of FeNTA is also responsible for such a low combustion velocity. The reaction products were further identified by SEM and XRD analysis. Accordingly, the reaction mechanisms for the examined nanothermites were mainly controlled by the oxygen transfer dynamics.

Electrophoretic Deposition and Thermo-Chemical Properties of Al/Fe2O3 Nanothermite Thick Films