Effect of Me/B‐Powder on the Ignition of High‐Energy Materials

Abstract

The study of the ignition characteristics of highenergy materials (HEMs) is important in solving a number of practical problems related to the assessment of explosion safety, the calculation of transition processes in power installation for various purposes (rocket and space technologies, weapons, pyrotechnics). This paper presents the experimental data on the thermal oxidation of ultrafine powder (UFP) based on Al/B, Ti/B, Ni/B, and Fe/B and the experimental characteristics of the ignition of HEM based on ammonium perchlorate, butadiene rubber, and metal fuel. In the course of processing thermal analysis data, the values of oxidation temperatures, the specific heat effect of the oxidation reaction, and the rate of weight gain of powder during heated at a constant rate of 10 °C/min in air were determined. It was shown that the oxidation of Ti/B and Ni/B UFPs begins at temperature of 490-500 °C, which is 60-70 °C lower than the onset oxidation temperature for boron powder. The use of 15.7 wt.% the mixed UFP based on Al/B, Ti/B, Ni/B or Fe/B in HEM reduces the ignition delay time by 7-50 % compared to boron-based HEM in the range of heat flux density from 60 to 200 W/cm 2 . Based on experimental data of the ignition delay time versus the heat flux density, the formal activation energy, the multiplication of the specific heat flux of the reactions by the pre-exponent and the ignition temperature are calculated which could be used in mathematical modeling of the ignition for composite solid propellant containing metal fuels.