Comparison study of the ignition and combustion characteristics of directly-written Al/PVDF, Al/Viton and Al/THV composites

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

“…It is also noted that a lower temperature mechanism favors K 2 AlF 5 formation over AlF 3 . 23,24 Wang et al 19 show the ame temperature of an Al + PVDF lm is $1500 K and the distribution of temperature within the reacting lm can range widely suggesting regions that could thermally favor K 2 AlF 5 over AlF 3 formation. Future work will elaborate more thoroughly on the evolution of temperature in reactions involving stress altered powders, but these results suggest that the greater gas generation over a longer duration associated with combustion of PS nAl + PVDF lms also disperses thermal energy enabling lower temperature kinetics to dominate evidenced by the formation of K 2 AlF 5 .…”

“…Now we can rewrite eqn (13)- (15) for new reference temperature T a ¼ 573 K at which there is no creep strain in the shell (s h ¼ 0) and stress and strain in the core are determined by eqn (19). These new equations are shown in eqn (20)- (22) and indeed, for 3 h c ¼ 0 and T ¼ T a we obtain s h ¼ 0 and eqn (19).…”

“…The results in eqn (19) show residual compressive stress and strain in the core at annealing temperature are much smaller than in the unrelaxed state at room temperature. Now we can rewrite eqn (13)- (15) for new reference temperature T a ¼ 573 K at which there is no creep strain in the shell (s h ¼ 0) and stress and strain in the core are determined by eqn (19). These new equations are shown in eqn (20)- (22) and indeed, for 3 h c ¼ 0 and T ¼ T a we obtain s h ¼ 0 and eqn (19).…”

“…From eqn (17) and (18), stress and strain in the Al core for fully relaxed shell depends on the difference between the annealing temperature and the temperature at which the shell is stressfree (coinciding with room temperature in this case). In these experiments, T 0 ¼ T r ¼ 298 K, T a ¼ 573 K and the stress and strain in the core are given by eqn (19).…”

Progress in Additive Manufacturing of Energetic Materials: Creating the Reactive Microstructures with High Potential of Applications

“…Thus, research has been concentrated on other fluoropolymers, including polyvinylidene fluoride (PVDF, 59 wt.% F), THV (73 wt.% F), and the commercial copolymers Fluorel™ FC-2175, Viton® A, FK-800, and Kel-F 800 [76]. Extensive comparison of directly written Al/PVDF, Al/Viton and Al/THV composites revealed differences in tensile stress, elasticity, burning rate (the highest one for PVDF) and flame temperature (the maximal value for THV) [177]. Alternatively, the dual-polymer-based composite resin system can be used to tune the curing, rheological and mechanical properties [178].…”