Effect of Heat Treatment Process and Composition on Deformation and Damage Behavior of WHA under Detonation Loading

The excellent material properties of tungsten heavy alloy (WHA) make it widely used in the military field. When used as killing elements of weapons, its dynamic mechanical properties under detonation loading directly determine the damage effect of weapons, which makes the research on its mechanical behaviors under high pressure and high strain rate loads such as detonation loading of great significance. In this paper, several WHAs with different compositions and processes are selected, and the mechanical properties and deformation and damage behavior under static explosion test are analyzed by combining macro and micro study, so as to provide guidance for the subsequent optimization of the performance design of WHA.

Hydrophobic nano SiO2 as flow-enhancing additives and flame retardant synergizes with CaCO3 to suppress gas explosion

The suppression effect of hydrophobic nano SiO2 of different concentrations as flow-enhancing additives synergizing with CaCO3 to inhibit gas explosions was systematically studied in a self-built LabVIEW-based explosion test platform.

Effects of Moisture Content on the Minimum Explosible Concentration of Aluminum Powder and the Related Mechanism

Aluminum powder has been widely applied to various industries. However, its high activity and high burn rate can cause serious explosion risks. Many factors affecting the explosion of aluminum powder have been determined, yet moisture content has not been included. In the present work, the minimum explosible concentrations of aluminum powders with different moisture contents were measured with a 20-liter explosion test apparatus using the explosion accident in Kunshan, China, as a study case. The experimental results suggest that the minimum explosible concentration of aluminum powder dramatically increases with the increase of its moisture content first and the increasing trend becomes slower as the moisture content further increased. The oxidation time has no significant effects on the minimum explosible concentration of aluminum power in 8 hours at room temperature. Further investigation suggests that the moisture lowers the explosion risk of aluminum powder by altering its surface oxide film, ignition, and combustion process. The low contents of moisture in the range of 0%-8% increase the minimum explosible concentration of aluminum powder by inhibiting the reaction kinetics and particle agglomeration, while high contents of moistures in the range of 8%-20% affect the minimum explosible concentration by the endothermic effect and oxygen dilution effect.

Study and Numerical Simulation on Explosion Propagation Characteristics of Lignite Dust

In order to reveal the explosion propagation law of lignite dust in 20L spherical explosion test device, the dust diffusion behavior and explosion propagation characteristics of lignite were studied by experiment and numerical simulation. The propagation process of dust explosion is studied by using high-speed camera and 20L spherical explosion test system, and the process of dust diffusion and explosion is simulated by using FLUENT software. The results show that the explosion propagation of lignite dust in the 20L spherical explosion test system has four different stages: the first explosion stage, the full explosion combustion stage, the continuous combustion stage and the combustion attenuation stage. The test results are slightly different from that of the fluent simulation of lignite dust explosion by using the high-speed camera to collect the dust explosion images. Results within the allowable error range, the experimental image of explosion combustion of lignite dust is well connected with the simulation results, which has a good display effect on the explosion propagation of lignite dust.

Effects of Liner Material and Structure on Penetration Characteristics of Small-Diameter Shaped Charge

Based on the AUTODYN-2D nonlinear dynamics platform, numerical simulations andexperiments are conducted to study the effect of 44mm small-caliber shaped charge on penetrationcharacteristics. Copper as the suitable material is chosen for small-caliber shaped charges, and theinfluence of the cone and the thickness of liner on the penetration of the jet into the steel target isobtained. The results show that the penetration depth decreases with the growth of the cone angle.Moreover, with the thickness of liner increasing, the penetration depth increases first and thendecreases. Based on the numerical simulation, structural parameters of the double cone liners wereoptimized: the optimum thickness liner was 1.2mm, and the optimal upper and lower cone of thedouble-cone liner was 40° and 60°. Besides, a static explosion test that the optimized double coneof the copper-type liner penetrated 45# steel targets is performed to verify the numerical simulation.