scholarly journals The shock wave compaction of ceramic powders

2019 ◽  
Vol 23 (Suppl. 2) ◽  
pp. 471-476 ◽  
Author(s):  
Andrey Buzyurkin ◽  
Evgeny Kraus ◽  
Yaroslav Lukyanov
Keyword(s):  
Shock Wave ◽  
Aluminum Oxide ◽  
Boron Carbide ◽  
Experimental Investigations ◽  
Ceramic Powders ◽  
Special Equipment ◽  
Explosive Compaction ◽  
Compact Sample ◽  
Explosion Pressure ◽  
Mathematical And Physical Modeling

Joint theoretical and experimental investigations have allowed to realize an approach with use of mathematical and physical modeling of processes of a shock wave compaction of ceramic powders. The aim of this study was to obtain a durable low-porosity compact sample. The explosive compaction technology is used in this problem because ceramic powders such as boron carbide and aluminum oxide is an extremely hard and refractory material. Therefore, its compaction by traditional methods requires special equipment and considerable expenses. In order to better understand the influence of the loading conditions and, in particular, to study the effect of detonation velocity, explosive thickness and explosion pressure on the properties of the final sample, the problem of compaction of the powder in an axisymmetric case using the conditions of the above experiments have been numerically solved. Thus, using the technology of explosive compaction, compact samples of boron carbide and aluminum oxide are obtained. On the basis of experimental and numerical studies of shock waves propagation, the optimum scheme and parameters of dynamic compaction of boron carbide and aluminum oxide are determined in order to maximize the density and the conservation of the samples after dynamic loading.

BULK NANOSTRUCTURED MATERIALS OBTAINED BY SHOCK WAVES COMPACTION OF ULTRAFINE TITANIUM AND ALUMINUM

2012 ◽  
Vol 05 ◽  
pp. 391-399
Author(s):  
NIKOLOZ M. CHIKHRADZE ◽  
CONSTANTIN POLITIS ◽  
MIKHEIL CHIKHRADZE ◽  
GEORGE ONIASHVILI
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Theoretical Calculations ◽  
Steel Tube ◽  
Hydrodynamic Theory ◽  
Full Density ◽  
Experimental Investigations ◽  
Disperse Powder ◽  
Explosive Compaction ◽  
Structural Investigations

Theoretical and experimental Investigations of shock wave consolidation processes of Ti - Al nano sized and ultra-disperse powder compositions are discussed. For theoretical calculations of the shock wave loaded materials were used the hydrodynamic theory and experimental adiabatic of Ti and Al . The normal and tangential stresses in the cylindrical steel tube (containers of Ti - Al reaction mixtures) were estimated using the partial solutions of elasticity theory. The mixtures of ultra-disperse Ti and nano sized (≤ 50nm) Al powder compositions were consolidated to full or near-full density by explosive-compaction technology. The ammonium nitride based industrial explosives were used for generation of shock waves. To form ultra-fine grained bulk TiAl intermetallics with different compositions, ultra-disperse Ti particles were mixed with nano-crystalline Al . Each reaction mixture was placed in a sealed container and explosively compacted using a normal and cylindrical detonation set-up. Explosive compaction experiments were performed in range of pressure impulse (5-20) GPa. X-ray diffraction (XRD), structural investigations (SEM) and micro-hardness measurements were used to characterize the intermetallics phase composition and mechanical properties. The results of analysis revealing the effects of the compacting conditions and precursor particles sizes, affecting the consolidation and the properties of this new ultra high performance alloys are discussed.

scholarly journals Theoretical and Experimental Investigation of Shock Wave Stressing of Metal Powders by an Explosion

2010 ◽  
Vol 5 (3) ◽  
pp. 71-78
Author(s):  
Andrey E. Buzyurkin ◽  
Evgeny I. Kraus ◽  
Yaroslav L. Lukyanov
Keyword(s):  
Shock Wave ◽  
Physical Modeling ◽  
Experimental Investigations ◽  
Powder Materials ◽  
Shock Wave Loading ◽  
Wave Loading ◽  
Metal Powders ◽  
Experimental Assembly ◽  
Mathematical And Physical Modeling ◽  
The Mathematical Model

Joint theoretical and experimental investigations have allowed to realize an approach with use of mathematical and physical modeling of processes of a shock wave loading of powder materials. Hugoniot adiabats of the investigated powder have been measured with a noncontact electromagnetic method. The mathematical model of elastic-plastic deformation of the powder media used in the investigation has been validated. Numerical simulation of shock wave propagation and experimental assembly deformation has been performed

EMISSION BY UNDERWATER EXPLOSIONS

Geophysics ◽  
1970 ◽  
Vol 35 (3) ◽  
pp. 419-435 ◽  
Author(s):  
M. Lavergne
Keyword(s):  
Shock Wave ◽  
Frequency Band ◽  
Experimental Investigations ◽  
Water Interface ◽  
Single Charge ◽  
Seismic Effects ◽  
Underwater Explosions ◽  
Seismic Efficiency ◽  
Marine Life ◽  
Air Water Interface

Theoretical and experimental investigations of the seismic effects of underwater explosions of dynamite charges are described. We investigate the acoustic efficiency in a broad frequency band and in the seismic frequency band, the partition of energy between the shock wave and bubble pulses, the seismic effects of cavitation due to ghost reflection at the air‐water interface, and the damage caused to marine life. Results concerning the variation of the seismic efficiency with shot conditions are given: the conclusion is that the seismic efficiency of charges of the order of 100 gm can be considerably increased by dividing the charges and by shooting at depth. Experiments show that two or three properly spaced 50 gm charges of dynamite, shot at a depth of about 12 m, give the same result as a single charge of about 5 to 15 kg shot at a depth of 1 m. CDP marine sections comparing caged charge shooting with conventional shooting in the same area are shown.

Research on Corner Structure Under Explosive Loading for War-Ship Cabin

2010 ◽  
Author(s):  
Xiangshao Kong ◽  
Shuangxi Xu ◽  
Weiguo Wu ◽  
Xiaobin Li ◽  
Yuanzhou Zheng
Keyword(s):  
Shock Wave ◽  
Nonlinear Dynamic ◽  
Failure Process ◽  
High Strength ◽  
Explosive Loading ◽  
Inclined Plate ◽  
Explosion Pressure ◽  
Conventional Structure ◽  
Dynamic Software ◽  
Plate Connection

For the warship cabin under explosive loading, the detail structure in cabin corner can easily be torn by the high-strength shock wave converging at the structure corner. In order to avoid that the crevasse occurs at the corner firstly, three strengthening structure forms were designed for the cabin corner: thickening connection, circular connection and inclined plate connection. Failure process of the joint in the two-cabin structure under the explosive loading was simulated by the nonlinear dynamic software DYTRAN. Comparing the response of the corner strengthening structure to that of the conventional structure, it was concluded that three strengthening structure forms changed failure mode of the cabin structure effectively and the crevasse initiated at the explosion pressure release hole on the transverse bulkhead, which reduced the tearing of the cabin corner. To seek more reasonable corner strengthening structure, the pressure and the stress on the bulkhead under the explosive loading of the three corner strengthening structures were compared. The results showed the inclined plate connection can prevent the shock wave from concentrating at the corner, decrease the stress on the longitudinal bulkhead, and resist the shock wave spreading into the inner cabins most effectively in the three strengthening forms.

scholarly journals Numerical and experimental investigations of buffet on a diamond airfoil designed for space launcher applications

2019 ◽  
Vol 30 (9) ◽  
pp. 4203-4218
Author(s):  
Jéromine Dumon ◽  
Yannick Bury ◽  
Nicolas Gourdain ◽  
Laurent Michel
Keyword(s):  
Shock Wave ◽  
Chaotic Behavior ◽  
Navier Stokes ◽  
Experimental Investigations ◽  
Fluid Structure ◽  
Content Type ◽  
Eddy Simulation ◽  
Numerical Predictions ◽  
Comprehensive Knowledge ◽  
Flow Effects

Purpose The development of reusable space launchers requires a comprehensive knowledge of transonic flow effects on the launcher structure, such as buffet. Indeed, the mechanical integrity of the launcher can be compromised by shock wave/boundary layer interactions, that induce lateral forces responsible for plunging and pitching moments. Design/methodology/approach This paper aims to report numerical and experimental investigations on the aerodynamic and aeroelastic behavior of a diamond airfoil, designed for microsatellite-dedicated launchers, with a particular interest for the fluid/structure interaction during buffeting. Experimental investigations based on Schlieren visualizations are conducted in a transonic wind tunnel and are then compared with numerical predictions based on unsteady Reynolds averaged Navier–Stokes and large eddy simulation (LES) approaches. The effect of buffeting on the structure is finally studied by solving the equation of the dynamics. Findings Buffeting is both experimentally and numerically revealed. Experiments highlight 3D oscillations of the shock wave in the manner of a wind-flapping flag. LES computations identify a lambda-shaped shock wave foot width oscillations, which noticeably impact aerodynamic loads. At last, the experiments highlight the chaotic behavior of the shock wave as it shifts from an oscillatory periodic to an erratic 3D flapping state. Fluid structure computations show that the aerodynamic response of the airfoil tends to damp the structural vibrations and to mitigate the effect of buffeting. Originality/value While buffeting has been extensively studied for classical supercritical profiles, this study focuses on diamond airfoils. Moreover, a fluid structure computation has been conducted to point out the effect of buffeting.

scholarly journals Explosive Compaction of Si3N4, SiC Ceramic Powders and Whiskers.

1992 ◽  
Vol 39 (4) ◽  
pp. 266-271
Author(s):  
Hideshi Miura ◽  
Shinji Yoshihara ◽  
Tadatoshi Honda
Keyword(s):  
Ceramic Powders ◽  
Explosive Compaction ◽  
Sic Ceramic

Study of Synthesis and Evaluation of Heat-Resistant Coatings Based on Silicon–Boron Carbide–Zirconium Boride–Aluminum Oxide Composite

2018 ◽  
Vol 44 (5) ◽  
pp. 450-454 ◽  
Author(s):  
I. B. Ban’kovskaya ◽  
A. N. Nikolaev ◽  
D. V. Kolovertnov ◽  
I. G. Polyakova
Keyword(s):  
Aluminum Oxide ◽  
Boron Carbide ◽  
Zirconium Boride ◽  
Oxide Composite ◽  
Heat Resistant

Laser Ablation Synthesis of Ceramic Powders

1990 ◽  
Vol 201 ◽  
Author(s):  
W. G. Fahrenholtz ◽  
S. R. Foltyn ◽  
K. C. Ott ◽  
M. Chadwick ◽  
D. M. Smith
Keyword(s):  
Thermal Analysis ◽  
Laser Ablation ◽  
Aluminum Oxide ◽  
Fine Powder ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
X Ray ◽  
Analysis Techniques ◽  
Aluminum Metal ◽  
Thermal Analysis Techniques

AbstractA pulsed excimer laser was used to ablate aluminum metal into an oxygen-containing atmosphere. The resulting fine powder was collected on a 0.1 μm filter and analyzed to determine structure and composition. Using a combination of TEM, EELS, and thermal analysis techniques, the product was found to be amorphous aluminum oxide, Al2O3. The morphology of the powders was investigated using SEM, TEM, and surface area measurements. The resulting powder was crystallized and examined by x-ray diffraction.

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