Enhanced reactivity of mechanically-activated nano-scale gasless reactive materials consolidated by coldspray

Bacciochini, A.; Radulescu, Matei I.; Charron-Tousignant, Yannick; Dyke, J. Van; Nganbe, Michel; Yandouzi, M.; Lee, J.J.; Jodoin, B.

doi:10.1016/j.surfcoat.2012.02.024

Cited by 29 publications

(19 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both of these conditions have been shown to increase the combustion velocity of the Ni/Al reaction. 4,25 The observed combustion velocities are also much faster than previously reported for both milled and unmilled Ni/Al reactives with micron sized powders. Taking into account both loose powder mixtures and cold-pressed compacts, typical combustion velocities have been reported to be on the order of 1-12 cm/s.…”

Section: -4mentioning

confidence: 49%

“…The combustion velocities in this work are 4-10 Â faster than those. However, the milling procedure utilized by Bacciochini et al 4 varied significantly from that of this work. In their work, the critical dry milling time was between 38-42 min, whereas the critical milling time for this work is between 17-17.5 min.…”

Section: -4mentioning

confidence: 93%

“…Taking into account both loose powder mixtures and cold-pressed compacts, typical combustion velocities have been reported to be on the order of 1-12 cm/s. 4,26 Recently, Bacciochini et al 4 reported combustion velocities for thermally ignited MA Ni/Al compacts cold-pressed to 40%-80% TMD in the range of 3-6 cm/s. The combustion velocities in this work are 4-10 Â faster than those.…”

Section: -4mentioning

confidence: 99%

“…[1][2][3] Numerous experimental and theoretical studies have been published on impact behavior and shock compression of metal-based reactive powder mixtures with metals such as Al, Ni, Si, Ti, W, Nb, and more. [1][2][3][4][5] Yet the fundamental mechanisms that govern the initiation and front propagation are not well understood. For example, their energy release characteristics depend on the mode of initiation, and reaction propagation, in a currently unpredictable way.…”

mentioning

confidence: 99%

“…4,5,10 Increasing the ignition sensitivities through MA occurs by changes in morphology, ductility, and hardness through cold working. This is achieved by high energy collisions between the particles and milling media.…”

mentioning

confidence: 99%

See 4 more Smart Citations

The role of microstructure refinement on the impact ignition and combustion behavior of mechanically activated Ni/Al reactive composites

Mason

Groven

Son

2013

Journal of Applied Physics

View full text Add to dashboard Cite

Metal-based reactive composites have great potential as energetic materials due to their high energy densities and potential uses as structural energetic materials and enhanced blast materials however these materials can be difficult to ignite with typical particle size ranges. Recent work has shown that mechanical activation of reactive powders increases their ignition sensitivity, yet it is not fully understood how the role of microstructure refinement due to the duration of mechanical activation will influence the impact ignition and combustion behavior of these materials. In this work, impact ignition and combustion behavior of compacted mechanically activated Ni/Al reactive powder were studied using a modified Asay shear impact experiment where properties such as the impact ignition threshold, ignition delay time, and combustion velocity were identified as a function of milling time. It was found that the mechanical impact ignition threshold decreases from an impact energy of greater than 500 J to an impact energy of $50 J as the dry milling time increases. The largest jump in sensitivity was between the dry milling times of 25% of critical reaction milling time (t cr ) (4.25 min) and 50% t cr (8.5 min) corresponding to the time at which nanolaminate structures begin to form during the mechanical activation process. Differential scanning calorimetry analysis indicates that this jump in the sensitivity to thermal and mechanical impact is dictated by the formation of nanolaminate structures, which reduce the temperature needed to begin the dissolution of nickel into aluminum. It was shown that a milling time of 50%-75% t cr may be near optimal when taking into account both the increased ignition sensitivity of mechanical activated Ni/Al and potential loss in reaction energy for longer milling times. Ignition delays due to the formation of hotspots ranged from 1.2 to 6.5 ms and were observed to be in the same range for all milling times considered less than t cr . Combustion velocities ranged from 20-23 cm/s for thermally ignited samples and from 25-31 cm/s for impacted samples at an impact energy of 200-250 J.

show abstract

Section: -4mentioning

confidence: 49%

Section: -4mentioning

confidence: 93%

Section: -4mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

The role of microstructure refinement on the impact ignition and combustion behavior of mechanically activated Ni/Al reactive composites

Mason

Groven

Son

2013

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

Effects of Shear Rate during Energetic Material Processing on Reactivity

et al. 2019

View full text Add to dashboard Cite

Energetic materials are often processed at high rates of deformation as colloidal slurries and then cured. The slurries are non-Newtonian colloidal solutions that exhibit changes in microstructure with variations in applied flow. This study shows that changes to microstructure due to applied flow affect the reactivity of energetic thin films. Energetic thin films of identical composition and geometry are prepared with different applied shear rates, which produce variations in the film microstructure by segregating smaller particles toward surfaces. Results show that films exhibit significant gains in flame speed with increasing shear rate. The differences in flame speed are linked to variations in microstructure. Specifically, densification of smaller particles near a boundary promote increased flame speeds. However, when particles become segregated, larger particles tend to contribute less to the overall reaction because they burn slowly compared to the smaller particles. When segregated, the larger particles may not be adding chemical energy to the reaction front because propagation is dominated by the more ignition sensitive smaller particles. This study demonstrates explicit changes in reactivity arising from changes in processing conditions that affect microstructure. Controlling applied shear rate introduces a new approach to regulating energetic material reactivity when processed using extrusion-based advanced manufacturing techniques.

show abstract

Progress in Additive Manufacturing of Energetic Materials: Creating the Reactive Microstructures with High Potential of Applications

Muravyev

Моногаров

Schaller

et al. 2019

Propellants Explo Pyrotec

View full text Add to dashboard Cite

The modern “energetic‐on‐a‐chip” trend envisages reducing size and cost while increasing safety and maintaining the performance of energetic articles. However, the fabrication of reactive structures at micro‐ and nanoscales remains a challenge due to the spatial limitations of traditional tools and technologies. These mature techniques, such as melt casting or slurry curing, represent the formative approach to design as distinct from the emerging additive manufacturing (3D printing). The present review discusses various methods of additive manufacturing based on their governing principles, robustness, sample throughput, feasible compositions and available geometries. For chemical composition, nanothermites are among the most promising systems due to their high ignition fidelity and energetic performance. Applications of reactive microstructures are highlighted, including initiators, thrusters, gun propellants, caseless ammunition, joining and biocidal agents. A better understanding of the combustion and detonation phenomena at the micro‐ and nanoscale along with the advancement of deposition technologies will bring further developments in this field, particularly for the design of micro/nanoelectromechanical systems (MEMS/NEMS) and propellant grains with improved performance.

show abstract

Enhanced reactivity of mechanically-activated nano-scale gasless reactive materials consolidated by coldspray

Cited by 29 publications

References 28 publications

The role of microstructure refinement on the impact ignition and combustion behavior of mechanically activated Ni/Al reactive composites

The role of microstructure refinement on the impact ignition and combustion behavior of mechanically activated Ni/Al reactive composites

Effects of Shear Rate during Energetic Material Processing on Reactivity

Progress in Additive Manufacturing of Energetic Materials: Creating the Reactive Microstructures with High Potential of Applications

Contact Info

Product

Resources

About