Thermite reduction of Ta2O5/SiO2 powder mixtures for combustion synthesis of Ta-based silicides

Yeh, C.L.; Huang, Yu-Shan

doi:10.1016/j.jallcom.2011.03.063

Cited by 13 publications

(5 citation statements)

References 26 publications

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“…Nanothermites refer to as thermites with reactants (fuel and oxidizers) size below 500 nm. As energy-generating materials, nanothermites find applications in material synthesis [1,2], low gas emission heat sources for welding and joining [3][4][5][6], initiation [7][8][9], and also on chip actuations [10][11][12][13]. Al fuel is by far the most employed metallic fuel because of its high oxidation enthalpy and low cost, despite the negative impact of the native alumina (Al2O3) coated on aluminum which penalizes the ignitability.…”

Section: Introductionmentioning

confidence: 99%

Pioneering insights into the superior performance of titanium as a fuel in energetic materials

Wu¹,

Singh²,

Julien³

et al. 2023

Chemical Engineering Journal

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Section: Introductionmentioning

confidence: 99%

Pioneering insights into the superior performance of titanium as a fuel in energetic materials

Wu¹,

Singh²,

Julien³

et al. 2023

Chemical Engineering Journal

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“…A thermite is defined as an energetic system consisting of a metal fuel (i.e., aluminum (Al)) and a metal oxide (i.e., copper oxide (CuO) or molybdenum trioxide (MoO 3 )). − These systems are widely studied due to their high energy densities and heats of combustion. − As energy-generating materials, thermite reactions have applications ranging from material synthesis − and alloying , to welding and joining. , Munir et al presented a thorough review on thermite applications, Fischer and Grublic tabulated thermochemical properties for hundreds of thermite reactions, and Koch presented the chemistry and application of fluorocarbon-based energetics . All of these reference materials provide a fundamental understanding of thermite reactivity and applications.…”

Section: Introductionmentioning

confidence: 99%

Activating Aluminum Reactivity with Fluoropolymer Coatings for Improved Energetic Composite Combustion

McCollum

Pantoya

Iacono

2015

ACS Appl. Mater. Interfaces

150

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Aluminum (Al) particles are passivated by an aluminum oxide (Al2O3) shell. Energetic blends of nanometer-sized Al particles with liquid perfluorocarbon-based oxidizers such as perfluoropolyethers (PFPE) excite surface exothermic reaction between fluorine and the Al2O3 shell. The surface reaction promotes Al particle reactivity. Many Al-fueled composites use solid oxidizers that induce no Al2O3 surface exothermicity, such as molybdenum trioxide (MoO3) or copper oxide (CuO). This study investigates a perfluorinated polymer additive, PFPE, incorporated to activate Al reactivity in Al-CuO and Al-MoO3. Flame speeds, differential scanning calorimetry (DSC), and quadrupole mass spectrometry (QMS) were performed for varying percentages of PFPE blended with Al/MoO3 or Al/CuO to examine reaction kinetics and combustion performance. X-ray photoelectron spectroscopy (XPS) was performed to identify product species. Results show that the performance of the thermite-PFPE blends is highly dependent on the bond dissociation energy of the metal oxide. Fluorine-Al-based surface reaction with MoO3 produces an increase in reactivity, whereas the blends with CuO show a decline when the PFPE concentration is increased. These results provide new evidence that optimizing Al combustion can be achieved through activating exothermic Al surface reactions.

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“…The highly exothermic nature of thermite reactions enables their use in a variety of energy generating applications such as material processing [1][2][3], welding and joining [4,5], and alloying [6,7]. This reaction occurs by oxygen transfer between a metal fuel (i.e., aluminum, Al) and metal oxide (i.e., copper oxide, CuO).…”

Section: Introductionmentioning

confidence: 99%

A slice of an aluminum particle: Examining grains, strain and reactivity

McCollum

Smith

Hill

et al. 2016

Combustion and Flame

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Micron-scale aluminum (Al) particles are plagued by incomplete combustion that inhibits their reactivity. One approach to improving reactivity is to anneal Al particles to increase dilatational (volumetric) strain which has also been linked to increased combustion performance. While optimal annealing temperatures have been identified (roughly 300 °C), little is known about cooling rate effects on particle combustion performance. This study examines the effect of quenching after annealing Al microparticles to 100, 200 and 300 o C on intra-particle dilatational strain and reactivity. Synchrotron X-ray diffraction analysis of the particles reveals the cooling rates in the range from 0.007 to 0.38 K/s have little effect on the dilatational strain of the aluminum-core, alumina-shell particles. The annealed and quenched Al particles were then combined with a metal oxidizer (copper oxide) to examine reactivity. Flame propagation experiments follow the same trend: flame speeds are unchanged until a critical annealing temperature of 300 °C is reached and performance is maintained for each annealing temperature regardless of cooling rate. These results show that altering the mechanical properties and combustion performance of Al particles is strongly dependent on the annealing temperature and unchanged with variation in cooling rate. The contributions from elastic and plastic deformation mechanisms on strain are also considered and additional experimental results are shown on the microstructure of an Al particle. Focused ion beam milling of an Al particle to electron transparency was combined with transmission electron microscope imaging in order to examine the microstructure of the Al particles. This confirmed that the Al microparticles have a polycrystalline structure shown by grains all exceeding 100 nm in size.

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Thermite reduction of Ta2O5/SiO2 powder mixtures for combustion synthesis of Ta-based silicides

Cited by 13 publications

References 26 publications

Pioneering insights into the superior performance of titanium as a fuel in energetic materials

Pioneering insights into the superior performance of titanium as a fuel in energetic materials

Activating Aluminum Reactivity with Fluoropolymer Coatings for Improved Energetic Composite Combustion

A slice of an aluminum particle: Examining grains, strain and reactivity

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