The effect of chemical composition and milling conditions on composite microstructure and ignition thresholds of Al Zr ball milled powders

Lakshman, Shashank Vummidi; Gibbins, John D.; Wainwright, Elliot R.; Weihs, Timothy P.

doi:10.1016/j.powtec.2018.11.012

Cited by 30 publications

(6 citation statements)

References 32 publications

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“…Despite these limitations, it should be noted that typical bomb calorimetry is completed under 30 atm, and when tests on a pure Al fuel of smaller sizes (~3 µm mean size) were performed at 1 atm in our custom bomb, there was no ignition or combustion of the Al implying that the utilization of intermetallic formation reactions for ignition benefits their reaction performance in this test environment. For completeness, it is noted that all of the particles tested here ignite at similarly low temperatures ranging from 600 to 700 K [16], as opposed to similarly sized micron Al, which ignites near 2100 K [64].…”

Section: Particle Geometry Effectsmentioning

confidence: 84%

“…Recently, there have been efforts to engineer metal fuels with independently tunable ignition and combustion properties by generating composite particles via high energy ball milling. 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].…”

Section: Introductionmentioning

confidence: 99%

“…Previous research on small quantities of ball milled Al:Zr particles has focused on studying their dual-phase combustion, which proceeds with Al vapor phase oxidation and Zr condensed state nitridation followed by Zr oxidation [16,44,45]. However, these studies lacked a measure of combustion efficiency, which is performed for the first time at small scales in this study.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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Al:Zr, Al-8Mg:Zr, and Al-38Mg:Zr nanocomposite particles fabricated by physical vapor deposition (PVD) and ball milling were reacted in 1 atm of pure O2 within a custom, highly-sensitive micro-bomb calorimeter. The heats of combustion were compared to examine the effect of particle size and composition on combustion efficiency under room temperature and in a fixed volume. All particles yielded ~60–70% of their theoretical maximum heat of combustion and exhibited an increase in heat over composite thin films of similar compositions, which is attributed to an increase in the surface area to volume ratio. The effect of particle size and geometry are mitigated owing to the sintering of the particles within the crucible, implying the importance of particle dispersion for enhanced performance. Vaporization of the metal species may transition between two diffusion flame species (Mg to Al). As Mg content is increased, more vaporization may occur at lower temperatures, leading to an additional stage of sintering. Physically intermixed Al and Mg oxides have been observed coating the surface of the particles, which implies a continuous transition of these vaporization processes. Such nano-oxides imply high vapor-flame combustion temperatures (>2700 K) and suggest viability for agent defeat applications.

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Section: Particle Geometry Effectsmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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“…Low rotational speeds (up to 200 rpm) imposed rather a small impact on the milling process as compared to 300–700 rpm [ 85 ]. A larger ball-to-powder mass ratio provided more extensive milling and contributed to particle size reduction, together with refinement of the additive inclusions and intermixing of the components in composite powders [ 86 , 87 ]. Process duration also was a critical parameter affecting the structural evolution of the metal particles.…”

Section: Introductionmentioning

confidence: 99%

Effects of Bi–Sn–Pb Alloy and Ball-Milling Duration on the Reactivity of Magnesium–Aluminum Waste-Based Materials for Hydrogen Production

et al. 2023

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In the present study, composite materials were elaborated of mixed scrap of Mg-based casting alloys and low melting point Bi–Sn–Pb alloy by high energy ball milling, and their reactivity in NaCl solution with hydrogen release was tested. The impacts of the additive content and ball milling duration on their microstructure and hydrogen generation performance were investigated. Scanning electron microscopy (SEM) analysis revealed significant microstructural transformations of the particles during milling, and X-ray diffraction analysis (XRD) proved the formation of new intermetallic phases Mg3Bi2, Mg2Sn, and Mg2Pb. The said intermetallic phases were anticipated to act as ‘microcathodes’ enhancing galvanic corrosion of the base metal. The dependency of the samples’ reactivity on the additive content and milling duration was determined to be nonmonotonic. For the samples with 0, 2.5, and 5 wt.% Rose alloy, ball-milling during 1 h provided the highest hydrogen generation rates and yields (as compared to 0.5 and 2 h), while in the case of the maximum 10 wt.%, the optimal time shifted to 0.5 h. The sample activated with 10 wt.% Rose alloy for 0.5 h provided the highest ‘metal-to-hydrogen’ yield and rapid reaction, thus overperforming those with lower additive contents and that without additives.

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“…In addition, the Weihs group fabricated the reactive Al/Zr multilayer foils by DC magnetron sputtering [28,29]. Recently, they have also synthesized a variety of AlÀ Zr alloys and composite powders by ball milling and physical vapor deposition (PVD) and tested them in various ignition and combustion experiments [30,31]. However, the powders prepared by these methods have a low degree of sphericity.…”

Section: Introductionmentioning

confidence: 99%

Preparation, Microstructure and Thermal Property of ZrAl₃/Al Composite Fuels

Zou

Shi

et al. 2019

Propellants Explo Pyrotec

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ZrAl 3 /Al composite fuels x = 10,20,30, 40, 50, 53 wt.%) were prepared by the non-consumable arcmelting technique and close-coupled gas-atomization. In order to study the effects of the zirconium content and the oxygen partial pressure on the thermal properties of composite fuels, X-ray diffraction, scanning electron microscopy, TG-DTA and DSC were used to characterize the composite fuels, respectively. The result shows that the addition of zirconium leads to the formation of a special structure inside the powder, promoting the oxidation of ZrAl 3 /Al composite fuels. Besides, non-selective oxidation of ZrAl 3 played an important role in promoting the oxidation process. The oxygen bomb experiment was conducted to evaluate the combustion performance of ZrAl 3 /Al composite fuels. Oxygen bomb experiments show that the gravimetric combustion enthalpy of the composite fuels decreases linearly with the increase of zirconium content, and increases with the increase of oxygen partial pressure. However, the volumetric combustion enthalpy decreases first and then increases with the increase of zirconium content, and shows a general upward trend when the partial pressure of oxygen reaches 2.5 MPa or more. The pressure curve indicates that the Al-53Zr composite fuels have the maximum pressure propagation rate (dP/dt) max (which characterizes the maximum flame propagation rate and higher energy releasing rates) in the prepared series of composite fuels. The study demonstrates a complete combustion of ZrAl 3 /Al composite fuels under high pressure. ZrAl 3 /Al composite fuels could be considered as a very promising energetic additive in the field of new-energetic material.

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The effect of chemical composition and milling conditions on composite microstructure and ignition thresholds of Al Zr ball milled powders

Cited by 30 publications

References 32 publications

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

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

Effects of Bi–Sn–Pb Alloy and Ball-Milling Duration on the Reactivity of Magnesium–Aluminum Waste-Based Materials for Hydrogen Production

Preparation, Microstructure and Thermal Property of ZrAl₃/Al Composite Fuels

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The effect of chemical composition and milling conditions on composite microstructure and ignition thresholds of Al Zr ball milled powders

Cited by 30 publications

References 32 publications

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

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

Effects of Bi–Sn–Pb Alloy and Ball-Milling Duration on the Reactivity of Magnesium–Aluminum Waste-Based Materials for Hydrogen Production

Preparation, Microstructure and Thermal Property of ZrAl3/Al Composite Fuels

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Preparation, Microstructure and Thermal Property of ZrAl₃/Al Composite Fuels