Determination of detonation velocity and pressure for MCX-6100

Abstract

Independent of the application of an explosive composition there are certain properties that are important to know. Performance depends on properties as detonation velocity and detonation pressure. Sensitivity of munitions depend on properties such as critical diameter to fulfil IM requirements. MCX-6100 is one of the new compositions developed with large critical diameter to withstand shock threat in the form of Bullet Attack, Fragment Impact, Sympathetic Reaction or Shape Charged Jet Attack. MCX-6100 is a composition developed and produced by Chemring Nobel. It is a melt-cast composition with potential application as filling in large calibre like 120 mm and 155 mm shells. We have characterized MCX-6100 due to the potential for utilisation in these ammunition types. MCX-6100 has DNAN as binder. The solid filler is a mix of NTO and RDX. Nominal content for MCX-6100 is 53/32/15 (NTO/DNAN/RDX). Selecting DNAN as binder makes it possible to use the same filling plants as for TNT or TNT based compositions to fill MCX-6100 into warheads. Different samples of MCX-6100 have been characterized with regard to critical diameter, detonation velocity and detonation pressure. In addition theoretical calculations of performance at different densities have been performed with Cheetah 2.0. The obtained quality of the casted test items with regard to density of the fillings has variations. Most items have a density of 96+2 % of Theoretical Maximum Density (TMD). X-ray images of cylindrical charges show lower density in the upper part of the charges than in the bottom. In addition the casted items contain some bubbles, also mostly in the upper part of the charges. The applied casting process has indisputable potential for improvement. Measurements of critical diameter for MCX-6100 CH 6079/13 seem relatively reproducible. 5 conical charges have been tested giving a critical diameter of 19.1+ 1.4 mm or 19.7 + 0.8 mm if the 4 most equal results are considered. Detonation velocity has been determined for both cylindrical charges with diameter 36+1 mm and for conical charges with largest diameter 30 mm. Detonation velocity varied with density of the test items. The average detonation velocity for 4 cylindrical test items having an average density of 1.71+0.02 g/cm3 was measured to be 7199+81 m/s. This result is 3-400 m/s lower than the theoretical calculated value with Cheetah 2.0. For the conical charge the detonation velocity between charge diameter 27 mm and 24 mm was measured to be 6281 m/s and for charge diameter between 24 mm and 21 mm to be 4685 m/s. Detonation pressure determined by the Plate Dent test for 6 test charges was measured to 190+ 7 kbars. As for the detonation velocity this result is lower than the theoretical calculated value by Cheetah 2.0. The difference is 30+10 kbar.