Combustion of explosively dispersed Al-Mg-Zr composite particles

Measuring Heat Production from Burning Al/Zr and Al/Mg/Zr Composite Particles in a Custom Micro-Bomb Calorimeter

“…Previous research has shown that these Al/Zr composite particles burn in a dual-phase (vapor oxidation and condensed nitridation/oxidation), which results in particles with a higher extent of combustion than observed here [45]. The overall decrease in heat output from the theoretical value may be a result of this dual-phase combustion not proceeding to completion, as the combustion efficiency of similar Al/Mg/Zr composite particles is 80-90% in a larger chamber under different ignition conditions [21]. Further, given that the addition of Mg does not lower the theoretical heat of combustion significantly, the reduced measured heat of combustion for the Al-38Mg:Zr particles, compared with the other particle compositions, is attributed to other potential sources.…”

“…For example, the average reactant spacing of the Al and Zr species within the microstructure can be varied to both lower their ignition temperature relative to pure Al of similar sizes and tune their ignition temperature [16]. The chemistry and size of the particles can be altered to control the energy and duration of combustion through the formation of oxides and nitrides [17][18][19][20][21][22]. Intermetallic reactions have been utilized in materials of varying compositions and structures [23,24] such as mechanically fabricated foils and particles [25][26][27][28][29] and vapor deposited laminate foils [30][31][32][33][34][35][36][37].…”

“…However, these studies lacked a measure of combustion efficiency, which is performed for the first time at small scales in this study. Other work has added Mg to generate an Al/Mg/Zr composite in order to assess the effect on combustion efficiency, maximum temperatures, burn rate, and so on [21,46]. Mg has also been added to Al and has been shown to decrease ignition delays and increase burn rates [47][48][49][50][51].…”

“…Comparisons with previously published data of the combustion efficiency of reactive thin film systems of the same composition are made. This work provides new comparisons with larger scale explosive testing of powders [21], which effectively provides dynamic bomb calorimetry measurements in a much larger fixed-volume chamber.…”

Influences of Multilayer Graphene and Boron Decoration on the Structure and Combustion Heat of Al3Mg2 Alloy

“…In addition to the high purity Al powder, Al-based alloys such as Al–Mg binary alloys have been investigated as additive materials for propellants. To improve the combustion performance of Al–Mg-based micron particles, zirconium particles are modulated to the matrix [ 6 ]. The results clearly showed that compared to commercial Al powder, the combustion efficiency of the composite materials increases from 30% to 80–90%.…”