Temperature Of Detonation Products Research Articles

Research of detonation products of RDX/Al from the perspective of composition

Aluminized explosives exhibit excellent performance because the oxidation of aluminum (Al) powders enhances the pressure and temperature of detonation products. However, the equation of state (EOS) of detonation products has not been understood well. In the present study, we conducted long-time tests (approximately 1 ms) of a metal rod driven by detonation products of RDX, RDX/LiF, and RDX/Al. In addition, we used laser velocimetry (PDV) to measure the freesurface velocity of the rod. Thermochemical code DLCHEQ was successfully applied to the hydrodynamic program SSS to perform the rod-driven test, and a novel method was established to study the EOS of detonation products from the perspective of composition. The reliability of DLCEHQ was validated by a small deviation (<10%) between the experimental rod free-surface velocity of RDX and the calculated results; the deviation was considerably less than that from the results obtained using the JWL EOS and ideal-gas EOS. The endothermic process and the reaction of Al powders (Al+H2O+NO+CO2→CO+H2+N2+Al2O3) were analyzed by calculating the rod free-surface velocity of RDX/LiF and RDX/Al, respectively. The results of the present study demonstrated that the thermodynamic state of Al powders has notable influence on the EOS of aluminized detonation products, and the findings were compared with those of previous studies. First, the temperature equilibrium between Al powders and CHNO products is not always achieved, and the disequilibrium is more obvious when the reaction of Al powders is stronger. Second, the reaction rate of Al powders depends on pressure and Al content. Finally, the endothermic process of Al powders has a high contribution to the decrease in the work ability of RDX/Al instead of the gasconsumption mechanism of the Al reaction. More than half of the reaction heat of Al powders is used to heat itself, whereas the gas consumption during the reaction is negligible.

A study on biological properties of titanium implants coated with multisubstituted hydroxyapatite

In this work, it was found that the composition of hydroxyapatite coatings deposited on a titanium substrate depends on the temperature of detonation products and on the composition of the initial explosive mixture. Depending on the detonation mode, it was possible to obtain a coating of oxyhydroxyapatite containing or not containing an admixture of other calcium orthophosphates. It was shown for the first time that the structure of multisubstituted Zn–Si-hydroxyapatite and Ag–Zn–Si-hydroxyapatite with substitution degree x(Zn) = x(Si) = 0.2 and x(Ag) = 0.1 has lower thermal stability as compared to unsubstituted hydroxyapatite. The formation of a small amount of the α-Ca3(PO4)2 phase upon detonation deposition of the multisubstituted hydroxyapatites was obviously due to structural transformations that occurred when the material was heated by the detonation products. In vivo biological testing of titanium implants coated or not coated with hydroxyapatite revealed that the coating significantly accelerates osteogenesis in the gap between native bone and the implant; this acceleration improved implant fixation. In animals with the uncoated plates, fibrogenesis processes significantly outstripped the osteogenesis. The presence of Zn and Si ions in the apatite coating had a potentiating influence on the osteoinduction caused by hydroxyapatite. Osteogenesis in this case was more complete and characterized by pronounced processes of mineralization of the bone plates. The addition of Ag ions to the Zn–Si-hydroxyapatite at a concentration of 1 at.% did not impair its osteogenic activity and did not have a toxic effect on bone tissue, while imparting antibacterial properties to the material.

Relaxation and Temperature of Explosive Detonation Products

The causes of changing temperature of gaseous energy-carrier under explosive loosening of a rock mass are considered. An equation is proposed to calculate the temperature of detonation products in a state of relaxation.

Temperature of detonation products with explosion in a chamber

There is an opinion that during the expansion of detonation products in a closed space their temperature generally drops and remains lower than the temperature directly ahead of the detonation wave. This paper seeks to calculate the temperature distribution occurring in the spherically symmetric explosion of a charge in a blasting chamber. It appeared that in a appreciable portion of the detonation products mass temperatures are reached which exceed by several factors the Chapman-Zhuge temperature. This paper explains that this effect is mainly connected not with spherical accumulation but with the complex flow structure during expansion of the detonation products and the subsequent circulation of detonation waves within the chamber.