Fusible Castable Explosive Composition with Optimized Particle Size

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Solution Overview

Problem

Existing meltable/castable explosive compositions struggle to increase the proportion of Hexogen (RDX) relative to oxynitrotriazole (ONTA) without reducing the insensitivity of the composition, which is essential for reducing vulnerability to external attacks.

Innovation Solution

A meltable/castable explosive composition with a fusible part of Trinitrotoluene and a solid part comprising oxynitrotriazole and insensitive Hexogen, where the Hexogen has a particle size between 315 micrometers and 800 micrometers, and ONTA has a particle size between 200 micrometers and 400 micrometers, along with an apparent density greater than or equal to 0.95 g/cm³, optimizing particle size cuts and morphology to reduce porosity and enhance insensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the proportion of Hexogen (RDX) is increased relative to oxynitrotriazole (ONTA) to improve detonic performance, then the blast effect and detonation speed are enhanced, but the insensitivity of the explosive composition is reduced

Engineering Contradiction:
Improvedetonic performanceVSAvoidinsensitivity
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the particle size of Hexogen (315-800 micrometers) and ONTA (200-400 micrometers), and by specifying the apparent density of ONTA (≥0.95 g/cm³). These parameter optimizations allow the composition to achieve both high detonic performance and maintained insensitivity, resolving the contradiction between power and reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite explosive composition combining multiple components (Hexogen, ONTA, and other explosives) with specific proportions and particle size distributions. This composite approach allows the synergistic interaction between components to achieve high detonic performance while the carefully selected particle sizes and densities maintain the overall insensitivity of the mixture.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the particle size of insensitive Hexogen is reduced to improve insensitivity, then the sensitivity to impact is reduced, but the porosity of the composition increases

Engineering Contradiction:
ImproveinsensitivityVSAvoidporosity
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent optimizes the particle size parameter of insensitive Hexogen to the range of 315-800 micrometers, which is coarser than traditionally used sizes. This parameter optimization, combined with specifying ONTA particle size (200-400 micrometers) and apparent density (≥0.95 g/cm³), achieves a balance between maintaining insensitivity and minimizing porosity to less than 10% after casting.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The composition achieves reduced sensitivity and increased detonation performance while maintaining insensitivity, with porosity minimized to less than 10% after casting, effectively resisting shock and thermal stresses, and demonstrating improved resistance to heating tests.

Implementation Method 1

a fusible part formed of at least one fusible explosive... Trinitrotoluene... melting and casting process

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

reduced vulnerability... resisting shock and thermal stresses... vulnerability tests... bullet impact, fire resistance

Methodology Applied
Scientific EffectShock resistance:

Data Source

PatentEP2516355B1Fusible/castable explosive composition having low vulnerability
Publication Date: 2017.08.23 NEXTER MUNITIONS SA
  • EP2516355B1 patent drawingFigure 1~2

AI summary

The invention relates a fusible/castable explosive composition having reduced vulnerability, which comprises a fusible portion consisting of at least one fusible explosive and a solid portion comprising oxynitrotriazole (ONTA) and cyclonite (RDX). Said composition is characterized in that the cyclonite is a low-sensitivity cyclonite, the particle size of the insensitive cyclonite being between 315 micrometers and 800 micrometers, whereas the particle size of the ONTA is between 200 micrometers and 400 micrometers, the ONTA further having an apparent density greater than or equal to 0.95 g/cm3. The invention finds use in loading projectiles by means of casting.