Underwater Explosive Behaviour of Compositions Containing Nanometric Aluminium Powder

2003 ◽  
Vol 800 ◽  
Author(s):  
Leslie R Bates
Keyword(s):  
Energy Release ◽  
Reaction Zone ◽  
Zone Length ◽  
Aluminium Powder ◽  
Explosive Performance ◽  
Explosive Properties

ABSTRACTResults from research aimed towards the understanding of the effect that ultrafine aluminium powder has on the explosive performance of underwater explosives are presented. A series of aluminised explosive compositions using a commercially available nanometric aluminium powder (Alex) have been prepared and quantified underwater. The results have been compared with the corresponding compositions using conventional aluminium powders. An enhancement in explosive properties can be seen. The effect is not universal but can be related to the reaction zone length, and time, of the base explosive being sufficiently long for the oxidation of the aluminium, with its substantial energy release, to take place in or close to the reaction zone.

scholarly journals Acceleration and heating of metal particles in condensed matter detonation

2012 ◽  
Vol 468 (2142) ◽  
pp. 1564-1590 ◽  
Author(s):  
Robert C. Ripley ◽  
Fan Zhang ◽  
Fue-Sang Lien
Keyword(s):  
Reaction Zone ◽  
Volume Fraction ◽  
Density Ratio ◽  
Particle Diameter ◽  
Solid Particles ◽  
Metal Particles ◽  
Solid Loading ◽  
Shock Propagation ◽  
Zone Length ◽  
Detonation Shock

For condensed explosives, containing metal particle additives, interaction of the detonation shock and reaction zone with solid inclusions leads to high rates of momentum and heat transfer that consequently introduce non-ideal detonation phenomena. During the time scale of the leading detonation shock crossing a particle, the acceleration and heating of metal particles are shown to depend on the volume fraction of particles, dense packing configuration, material density ratio of explosive to solid particles and ratio of particle diameter to detonation reaction-zone length. Dimensional analysis and physical parameter evaluation are used to formalize the factors affecting particle acceleration and heating. Three-dimensional mesoscale calculations are conducted for matrices of spherical metal particles immersed in a liquid explosive for various particle diameter and solid loading conditions, to determine the velocity and temperature transmission factors resulting from shock compression. Results are incorporated as interphase exchange source terms for macroscopic continuum models that can be applied to practical detonation problems involving multi-phase explosives or shock propagation in dense particle-fluid systems.

Dependence of Critical Diameter of Emulsion Explosive on Density in Steel Confinement

2013 ◽  
Vol 8 (3) ◽  
pp. 128-134
Author(s):  
Sergey Rafeichik
Keyword(s):  
Reaction Zone ◽  
Acoustic Impedance ◽  
Detonation Front ◽  
Initial Density ◽  
Critical Diameter ◽  
Emulsion Explosive ◽  
Emulsion Explosives ◽  
Minimum Diameter ◽  
Zone Length ◽  
Strong Confinement

Emulsion explosives (EMX) based on fine emulsion matrix are characterized by high detonation ability. Critical diameter (as minimum diameter when detonation occurs) and reaction zone length are known in the case of thin confinement with low acoustic impedance. The dependence of critical diameter of EMX in steel confinement with high acoustic impedance was examined in the range of initial density 0,75–1,37 g/cm3 . Density was varied by the concentration of glass microballoons, which were used as the sensitizer. It was shown experimentally, that characteristic value is /2 1 cr R d a  in the case of strong confinement. This can be due to the decrease of detonation front curvature. Comparison was made between the values of critical diameter in weak and strong confinement. The main distinction is that such dependence in strong confinement is lower and almost monotonic. This can indicate the influence of some processes besides lateral rarefaction wave. Period of reaction is closely connected with critical diameter and reaction zone length. Model based on heterogeneous kinetic of heating of emulsion surrounding single microballoon was proposed to describe the experimental dependence of the reaction zone time of EMX on concentration of microballons

Reduction of detonating liquid nitromethane’s chemical reaction-zone length by chemical sensitization

2005 ◽  
Vol 17 (9) ◽  
pp. 096102 ◽  
Author(s):  
Ray Engelke ◽  
Stephen A. Sheffield ◽  
Howard L. Stacy ◽  
John P. Quintana
Keyword(s):  
Reaction Zone ◽  
Chemical Reaction ◽  
Zone Length ◽  
Chemical Reaction Zone

scholarly journals Study on the Detonation Reaction-zone and Energy Release Characteristics of a Cast HMX-based PBX

2019 ◽  
Vol 16 (3) ◽  
pp. 380-398 ◽  
Author(s):  
Kaiyuan Tan ◽  
Yong Han ◽  
Guan Luo ◽  
Ming Yin ◽  
Shanggang Wen ◽  
...  
Keyword(s):  
Energy Release ◽  
Reaction Zone ◽  
Detonation Reaction

TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

1988 ◽  
Vol 46 ◽  
pp. 738-739
Author(s):  
G. Das ◽  
R. E. Omlor
Keyword(s):  
Titanium Alloys ◽  
Reaction Zone ◽  
Carbon Layer ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Sic Fibers ◽  
Sic Fiber ◽  
The Matrix ◽  
Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

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