Preparation, ignition, and combustion of mechanically alloyed Al-Mg powders with customized particle sizes

Aly, Yasmine; Hoffman, Vern K.; Schoenitz, Mirko; Dreizin, Edward L.

doi:10.1557/opl.2013.145

Cited by 5 publications

(4 citation statements)

References 21 publications

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“…Two Al-Mg alloy powders with Al/Mg mass ratio of 50:50 were used in thermo-gravimetric (TG) experiments. An atomized spherical alloy, -270 Mesh was provided by Valimet Inc. A mechanically alloyed powder was prepared at NJIT as described in detail elsewhere [19][20][21]. Briefly: starting materials for the mechanically alloyed powder were elemental powders of Al (Atlantic Equipment Engineers, 99.8% pure, -325 Mesh) and Mg (Alfa-Aesar, 99.8% pure, -325 Mesh).…”

Section: Methodsmentioning

confidence: 99%

Oxidation of differently prepared Al-Mg alloy powders in oxygen

Nie

Schoenitz

Dreizin

2016

Journal of Alloys and Compounds

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Powders of both commercial atomized spherical Al-Mg alloy and mechanically alloyed Al-Mg were oxidized in oxygen using thermo-gravimetry (TG). For both powders, the Al/Mg mass ratio was equal to 1. Fully and partially reacted powders were recovered and characterized using scanning electron microscopy and x-ray diffraction. Voids grow within oxidized alloy particles for both atomized and mechanically alloyed powders. Results were interpreted accounting for the measured particle size distribution for the spherical powder and distributing the TG-measured weight gain among the individual particle size bins. The reaction interfaces were always located at the internal surface of the oxide shell as determined by matching the oxidation dynamics for particles with the same sizes but belonging to powders with different particle size distributions. Thus, the reaction is always rate limited by inward diffusion of oxygen ions through the growing oxide shell. Two oxidation stages were identified for both materials. Both Al and Mg oxidize during both observed oxidation stages. The second oxidation stage is caused by formation of the spinel phase, most likely occurring at a threshold temperature. In the present measurements, the step in the oxidation rate, or switch between the oxidation stages, occurs when the oxide shell grows above a certain thickness of approximately 1.5 µm. The apparent activation energy during the first oxidation stage energy changes during the first oxidation stage suggesting that more than one reaction occur in parallel, e.g., causing formation of MgO and amorphous alumina. For the second oxidation step, controlled by diffusion of oxygen through spinel layer, the activation energy remains nearly constant around 185 kJ/mol.

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Section: Methodsmentioning

confidence: 99%

Oxidation of differently prepared Al-Mg alloy powders in oxygen

Nie

Schoenitz

Dreizin

2016

Journal of Alloys and Compounds

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“…Some of the trends shown are based on more than one set of measurements reported in the literature. The data for aluminum come from refs . for boron, from refs .…”

Section: Rates Of Heat Release For Rsmsmentioning

confidence: 99%

“…Characteristic burn times of particles of different sizes for selected metal fuels reported in the literature: aluminum, boron, titanium, and magnesium …”

Section: Rates Of Heat Release For Rsmsmentioning

confidence: 99%

Reactive Structural Materials: Preparation and Characterization

Hastings

Dreizin

2017

Adv Eng Mater

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Reactive structural materials, which can serve both as structural elements as well as a source of chemical energy released upon initiation have emerged as an important class of metal-based composites for use in various energetic systems. Such materials rely on a variety of exothermic reactions, from oxidation to formation of metal-metalloid and intermetallic phases. The rates of these reactions are as important as the energy that may be released, in order for them to occur at the time scales compatible with the requirements of applications. Therefore, chemical composition, scale at which reactive components are mixed, and the structure and morphology of materials are important and can be controlled by the method of preparation and compaction of the composite materials. Methods of preparation of the composite structures are briefly reviewed as well as methods of characterization of their mechanical and energetic properties. In addition to common thermo-analytical and static mechanical property measurements, dynamic tests of mechanical properties as well as ignition and combustion experiments are necessary to understand the fragmentation, initiation, and heat release expected for these materials when they are stimulated by an impact, shock, or rapid heating. Reaction mechanisms are studied presently for the thin layers and small samples of reactive materials initiated in carefully designed experiments. In other experiments, impact and explosive initiation are characterized for larger material compacts in the conditions imitating practical scenarios. Examples of results describing thermal, impact, and explosive initiation of some of the reactive materials are presented.

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“…To some degree, the alloy powders mentioned above can shorten the ignition delay time, reduce the ignition temperature and strengthen the degree of oxidation. They also have higher energy releasing efficiency and energy releasing rates [8][9][10]. However, these metals have some essential shortcomings.…”

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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Preparation, ignition, and combustion of mechanically alloyed Al-Mg powders with customized particle sizes

Cited by 5 publications

References 21 publications

Oxidation of differently prepared Al-Mg alloy powders in oxygen

Oxidation of differently prepared Al-Mg alloy powders in oxygen

Reactive Structural Materials: Preparation and Characterization

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

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Preparation, ignition, and combustion of mechanically alloyed Al-Mg powders with customized particle sizes

Cited by 5 publications

References 21 publications

Oxidation of differently prepared Al-Mg alloy powders in oxygen

Oxidation of differently prepared Al-Mg alloy powders in oxygen

Reactive Structural Materials: Preparation and Characterization

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

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Product

Resources

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