Bor Katkılı Duyarsız Tahrip Gücü Yüksek Yeni Patlayıcıların Geliştirilmesi

Abstract

Within the scope of this thesis, enhanced blast explosives containing magnesium-coated boron (MCB) and metal boride (AlB2, MgB2 and AlB12) based boron compounds have been developed and produced, which can be used instead of aluminum-based, polymer-bonded and castable enhanced blast explosives that is frequently used in ammunition systems and which can show better performance characteristics. These explosives contain energetic filler cyclotetramethylene tetranitramine (HMX) and metal fuels like MCB and metal borides (AlB2, MgB2 and AlB12) as solid component; as liquid components, the binder hydroxyl terminated polybutadiene (HTPB), plasticizer isodesyl pelargonate (IDP), catalyst triphenylbismuth (TPB) and dibutyltin dilaurate (DBTDL), wetting agent lecithin and hardener isophorone diisocyanate (IPDI) are included in a specific formulation.

In the first part of the thesis, characterization studies of HMXs and metal/metalloid/metal boride powders used as solid components in the reference and developed explosives with different average particle sizes were carried out by measuring their physical and mechanical properties (particle size distribution, true density, bulk density, tapped density, moisture and SEM) and for HMXs also their performance properties (calorific energy) and the results were evaluated.

In the next stage of the thesis, an explosive was produced using 40% magnesium coated boron (MCB) as metal fuel in a predetermined explosive formulation. However, it was observed that the MCB based explosive did not have the desired processability properties due to its high initial viscosity and curing rate. Considering that the initial viscosity of the MCB based explosive depends on the different average particle sizes of the HMXs in its content and their ratios to each other by weight, In order to reduce the initial viscosity of the explosive, the ratio of HMXs of different average particle sizes (Class 1 (d50=164µm) and Class 5 (d50=24µm)) to each other by weight was changed and HMXs of different classes (Class 2 (d50=36µm)/Class 3 (d50=317µm)) were used in the explosive at a ratio of 0.5. The results showed that the use of Class 2/Class 3 HMX at a ratio of 0.5 in the explosive brought the initial viscosity of the explosive to the limits of processability.

The amount and type of catalyst in the explosive, which is one of the parameters that are effective in the high curing rate of the explosive, were also changed and the amount of catalyst in the explosive was reduced and a different type of catalyst was also tried. As a result, it was observed that the use of 0.0006% DBTDL catalyst decreased the curing rate of the MKB based explosive and provided workability. Physical and mechanical properties (viscosity, true density, moisture, hardness, stress and strain), thermal properties (heat capacity, vacuum thermal stability, thermal conductivity coefficient, thermal expansion coefficient, VTS, glass transition temperature and autoignition temperature), sensitivity properties (friction sensitivity) and performance properties (calorific energy, detonation velocity, shock pressure and impulse) of MCB based explosive and aluminum and metal boride (AlB2, MgB2 and AlB12) based explosives produced in the same formulation, were measured and the properties of the explosives were compared with the properties of the reference aluminum based explosive. It was found that the thermal and performance properties of the AlB2 based explosive were much better than the reference explosive. As a result, the thesis study has shown that the compound of a metalloid such as boron, which is abundant in our country, with aluminum can be used successfully in the production of enhanced blast explosives.