CHARACTERIZATION OF INKJET PRINTED HIGH NITROGEN ENERGETIC MATERIALS AND BILAYER NANOTHERMITE

This thesis presents work on two major areas of research. The first area of research involves the use of a dual-nozzle piezoelectric inkjet printing system to print bilayer aluminum bismuth (III) oxide nanothermite samples. The combinatorial printing method allows for separate fuel and oxidizer inks to be printed adjacent to each other at prescribed offset distances. The effect of the bilayer thickness on the burning rate of the samples is investigated using high-speed imaging. Analysis of the burning rate data revealed that there is no statistically significant relationship between these two parameters. This result was used to determine the dominant processes that control the propagation rate in nanothermite systems. It was concluded that convective processes dominate the burning rate rather than diffusive processes. The second area of research involved synthesizing inks suitable for inkjet printing using two promising high nitrogen energetic materials called BTATz and DAATO_3.5. The performance of the developed inks was characterized using four experiments. The thermal stability and exothermic behavior of the inks were determined using DSC and TGA analysis. The results revealed that the inks are more thermally stable than the base materials. The inks were used to print lines that were subsequently used to determine burning rates. DAATO_3.5 samples were determined to have faster burning rates than BTATz. Closed pressure bomb experiments were conducted to determine the gas producing capability of the high nitrogen inks. BTATz samples showed better performance in terms of peak static pressures and pressurization rates. 3D printed microthrusters were developed to test the thrust performance of the inks. Peak thrust, total impulse, and specific impulse values are reported and were determined to be suitable for use with Class 1 micro-spacecraft. Finally, a microthruster array prototype was developed to demonstrate the capability to use additive manufacturing to create high packing density arrays.