Description:
TECHNOLOGY AREA(S): Weapons
OBJECTIVE: Develop energetic formulations that can function as a propellant and an explosive yet satisfy insensitive munition requirements.
DESCRIPTION: Next generation munitions addressing technology gaps, particularly for Air Superiority, are anticipated to generate higher lethality from smaller systems likely requiring advanced technology and potentially alternative approaches. One approach would be to develop an energetic formulation that is capable of serving as a common energy source which can be exploited as a fuel for propulsion to get the system to the target with the remainder used to provide the target defeat mechanism. This approach has the potential to alter the paradigm of missile/munition design since it increases system flexibility by allowing additional thrust control in the terminal encounter and/or utilizing the larger surface area of a case to mimic a larger warhead for either blast or fragment distribution near a target. While the energetic crystals within propellants and explosives are often similar indicating dual-mode potential, the formulations are different and optimized for their respective application. [1,2,3] Propellants are optimized to have certain burn rates and mechanical properties over a broad range of temperatures [-65°F to 165°F] in order to produce desired thrust in a controlled manner. For example, propellant formulations seek to avoid cracking that may occur with thermal-cyclic loading because a crack will result in a catastrophic failure since the propellant burn-rate will accelerate out of control and potentially detonate prematurely. The focus of this effort is on developing formulations that are capable of producing the desired thrust over a broad range of temperatures and yet can be easily detonated upon command when needed. The formulations will also need to consider requirements for passing insensitive munition requirements. [4]
PHASE I: Identify potential formulations that are capable of functioning as both a propellant and an explosive. Ideally, formulations will have a controlled burn rate, sensitive to pressure or some other throttling mechanism, yet can be detonated with the minimal initiation train. Initial characterization of the burn-rate and mechanical properties.
PHASE II: Detailed validation and systematic parametric sensitivity of formulations through mechanical property and burn-rate characterization over a broad range of temperatures and pressures. Assess the feasibility of passing IM requirements. Demonstration of dual-mode energetic material within a representative configuration. Demonstration would consist of burning the material with a motor, extinguishing burn, and detonating residual energetic material.
PHASE III: Within a Phase III effort it is anticipated that the small business would partner with a prime contractor to form a team that includes pertinent government representatives for guidance. Multiple near-term munition concepts may benefit from a dual-mode energetic and the team would tailor the energetic to the promising concepts. This process would involve assessments of how current designs (geometry, initiation, etc.) could be modified to exploit the dual-mode material as well as envision new designs based on performance. Additionally, the material would be evaluated to determine the feasibility of the energetic material to boost efficiency of secondary reactions within cases. Advanced demonstrations conducted by prime or sub-prime contractors in partnership with the small business and in coordination with the government would reveal advantages of the dual-mode energetic and create a commercialization path.
REFERENCES:
1: Goedert, Z., Sieg, G., Scale-up Of Cl-20 Propellant Formulations. Desensitization Of Cl-20, Accession Number: CPIAC-2009-0031CD, April 2009
2: Mason, M., et. al., Performance and Fragment Impact Testing of PBXC-135, an Insensitive CL-20 Based Plastic-Bonded Explosive, Accession Number: ADB403398, August 2014
3: Mason, M., et. al., Pbxc-135: A Reduced-sensitivity, High-performance, Plastic-bonded Explosive Based On Cl-20, Accession Number: CPIAC-2008-0006AH, May 2008
4: MIL-STD-2105D Hazard Assessment Tests for Non-nuclear Munitions
KEYWORDS: Dual-mode Energetics, Multi-mode Energetics, Multi-purpose Energetics, Dual-purpose Energetics, CL-20, HMX, RDX, Dual-mode Munitions, Multi-use Explosives, Advanced Propellants
