Thermite reactivity with ball milled aluminum-zirconium fuel particles

Woodruff, Connor; Wainwright, Elliot R.; Bhattacharia, Sanjoy K.; Lakshman, Shashank Vummidi; Weihs, Timothy P.; Pantoya, Michelle L.

doi:10.1016/j.combustflame.2019.09.028

Cited by 13 publications

(3 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this work a method of preliminary mechanochemical activation in a high-energy ball mill was used. This method makes it possible to obtain mixtures with high combustion rates [20][21][22]. A mixture of aluminium with copper oxide was chosen as the main object of research.…”

Section: Introductionmentioning

confidence: 99%

Explosive Burning of a Mechanically Activated Al and CuO Thermite Mixture

et al. 2022

View full text Add to dashboard Cite

The results of experiments to determine the role of structural schemes for the ignition of a mechanically activated thermite mixture Al–CuO and the formation of its combustion flame are presented. The reaction initiated in the bulk of the experimental assembly transforms into torch combustion in an open space. The dynamics of the volume of the flame reaction region was determined. The stage of flame formation has a stochastic character, determined by the random distribution of the reaction centres in the initial volume of the components. A high-speed camera, a pyrometer and electro contact sensors were used as diagnostic tools. The ultimate goal of the study was to optimize the conditions for the flame formation of this mixture for its effective use with a single ignition of various gas emissions.

show abstract

Section: Introductionmentioning

confidence: 99%

Explosive Burning of a Mechanically Activated Al and CuO Thermite Mixture

et al. 2022

View full text Add to dashboard Cite

show abstract

“…These new materials not only have high energy density, but also release their stored chemical energy in a rapid, safe and stable manner, upon ignition. A large part of the research is still dedicated to finding ways to modulate accurately the combustion wave velocity (m.s −1 to hundreds of m.s −1 ) in a reproducible way [14][15][16][17][18]. As the energy release rate is directly dependent on the equivalence ratio, size and morphology of the oxidizer and fuel, many research studies propose to manipulate the material formulation; however it requires expensive and time-consuming synthesis and characterization loops.…”

Section: Introductionmentioning

confidence: 99%

Elucidating the dominant mechanisms in burn rate increase of thermite nanolaminates incorporating nanoparticle inclusions

Julien¹,

Wang²,

Tichtchenko³

et al. 2021

Nanotechnology

View full text Add to dashboard Cite

It was experimentally found that silica and gold particles can modify the combustion properties of nanothermites but the exact role of the thermal properties of these additives on the propagating combustion front relative to other potential contributions remains unknown. Gold and silica particles of different sizes and volume loadings were added into aluminum/copper oxide thermites. Their effects on the flame front dynamics were investigated experimentally using microscopic dynamic imaging techniques and theoretically via a reaction model coupling mass and heat diffusion processes. A detailed theoretical analysis of the local temperature and thermal gradients at the vicinity of these two additives shows that highly conductive inclusions do not accelerate the combustion front while poor conductive inclusions result in the distortion of the flame front (corrugation), and therefore produce high thermal gradients (up to 1010 K.m−1) at the inclusion/host material interface. This results in an overall slowing down of the combustion front. These theoretical findings contradict the experimental observations in which a net increase of the flame front velocity was found when Au and SiO2 particles are added into the thermite. This leads to the conclusion that the faster burn rate observed experimentally cannot be fully associated with thermal effects only, but rather on chemical (catalytic) and/or mechanical mechanisms: formation of highly-stressed zones around the inclusion promoting the reactant mixing. One additional experiment in which physical SiO2 particles were replaced by voids (filled with Ar during experiment) to cancel the potential mechanical effects while preserving the thermal inhomogeneity in the thermite structure confirms the hypothesis that instead of pure thermal conduction, it is the mechanical mechanisms that dominate the propagation velocity in our specific Al/CuO multilayered films.

show abstract

“…Ball milling is a well-established, inexpensive and scalable technique for fabrication of different powdered materials [1,2]. For energetic materials including metastable alloys, Al/oxides reactive materials (RMs), ball milling technique allows their reactive properties to be enhanced through nano-structuring of the material [1,3].…”

Section: Introductionmentioning

confidence: 99%

Enhanced reactivity of copper complex-based reactive materials via mechanical milling

Wu¹,

Sevely²,

Pelloquin³

et al. 2021

Combustion and Flame

View full text Add to dashboard Cite

A prior investigation by the authors demonstrated that incorporating 25% of copper complex (Cu(NH3)4(NO3)2) into Al/CuO nanothermite enables to produce highly-reactive gasgenerating energetic composites for emerging micro-airbag applications. To further improve the decomposition of the copper complex into gaseous species (N2, O2, N2O), during the thermite reaction, we employed ball milling technique to diminish its grain size down to the nanoscale. Results show that premilling the copper complex i.e. refining its grains without much modifying their structures, increases the pressure generation and burn rate by a factor 1.5 and 2, respectively. It also maintains a high degree of performances along a wider range of thermite to copper complex mass ratio.

show abstract

Thermite reactivity with ball milled aluminum-zirconium fuel particles

Cited by 13 publications

References 30 publications

Explosive Burning of a Mechanically Activated Al and CuO Thermite Mixture

Explosive Burning of a Mechanically Activated Al and CuO Thermite Mixture

Elucidating the dominant mechanisms in burn rate increase of thermite nanolaminates incorporating nanoparticle inclusions

Enhanced reactivity of copper complex-based reactive materials via mechanical milling

Contact Info

Product

Resources

About