Transformative Energetics: A Pathway to Next Generation Munitions

Transcription

1 Transformative Energetics: A Pathway to Next Generation Munitions Merran Daniel, Andrew Hart, Arthur Provatas Energetic Systems and Effects Branch PARARI 2017 UNCLASSIFIED

2 Introduction UNCLASSIFIED DST plays a key role in positioning the ADF to fully exploit capabilities afforded by emerging weapons concepts Army Modernisation Lines of Effort: Next Generation Munitions, Novel Energy Weapons Transformative Energetics Enabling advanced weapons systems that offer disruptive performance gains and increasing the safety, agility and efficiency of munitions manufacture.

3 Transformative Energetics Lines of Effort Advanced Materials Nano-technology Processing Technology Resonant Acoustic Mixing 3D Printing of Energetics Next Generation Munitions

4 Nano-energetics An emerging field of energetic materials China, Russia and US are leaders amongst few active players US ARDEC labs nano-sized polymer coated RDX, HMX, TATB, CL-20, NTO Material properties change significantly at nano-scale (~0.1 µm) Higher surface area Increased chemical reactivity Enhanced mechanical properties Higher solubility Altered optical properties Smaller defect dimensions Performance Nano Energetics Traditional Materials Sensitivity Enhanced performance & safety effective energy utilisation in volume constrained, extreme environments

5 Nano-Processes and Methods Top-Down Processes Bead Milling Comminution process (media: liquid with <500µm ceramic beads) Maintains polymorph Scalable Bottom-Up Processes Complimentary techniques Spray Drying Crystallisation process Micron sized particles containing nano-sized EM encapsulated by binder Simple and scalable Best polymorph not always retained

6 Spray Drying: Büchi 290 closed loop system EM + Binder Dissolved in Organic solvent Atomisation - droplets evaporated Rapid co-precipitation yields nanocomposite granules Aspirator Process Variables Solution Feed Rate Atomizing Gas Rate Drying Temperature Nozzle Solvent Type Concentration of Solute Ref: Qiu et al, Powder Tech., 2015, 274, Drying Cyclone Product Outlet Chamber Separator Filter

7 Spray Drying: DST Program of Work RDX/HMX and FEM RDX with PVAc binder Alternative coatings to explore, inc. in support of 3D printing of energetics RDX with polyglyn More energetic binders to follow Priority: Material characterisation Sensitiveness, morphology, performance 1-15 µm nanostructured RDX granules

8 Resonant Acoustic Mixing (RAM) RAM is a new processing technique that utilises low frequency high-intensity acoustic energy to blend materials Fast Increased safety Versatile Environmental benefits UNCLASSIFIED Currently used for research, development and production of energetic materials globally Source: Resodyn Video: Resodyn

9 DST Group Resonant Acoustic Mixers LabRAM, 500g capacity LabRAM IIH, 1kg capacity

10 Industrial Resonant Acoustic Mixers RAM 5, 37kg capacity RAM 55, 420kg capacity

11 Continuous Acoustic Mixer Couples to RAM 5 Application Throughput (kg/hr) Dry powder 1080 Intermediate viscosity 100 High viscosity 8.2

12 RAM Applications In-situ mixing UNCLASSIFIED Dry powder mixing Mould. powder develop. High viscosity slurries Co-crystallisation Polymer coating Ref: Bolton et al, Cryst. Growth Des. 2012, 12, RDX + 10% MP22XF 1 min RDX + 10% MP22XF 30 min

13 3D Printing of Propelling Charges Disruptive technology prospect of better exploiting gun hardware performance limits. Integrated propelling charge design and arbitrary propellant geometries: Increased range, velocity, precision, uniformity, weapon life More agile and cost-effective (?) propelling charge development Reduced manufacturing footprint. Key challenges by 3D printing technology type: Structural integrity of print/build Printer feedstock options Achievable energy content; compatibility; curability Print precision UNCLASSIFIED

14 3D Printing of Propelling Charges Disruptive technology prospect of better exploiting gun hardware performance limits. Integrated propelling charge design and arbitrary propellant geometries: Increased range, velocity, precision, uniformity, weapon life More agile and cost-effective (?) propelling charge development Reduced manufacturing footprint. Key challenges by 3D printing technology type: Structural integrity of print/build Printer feedstock options Achievable energy content; compatibility; curability Print precision UNCLASSIFIED 10% m.v increase

15 Research Thrusts Ballistics Research Component Model, optimise, design and test new gun propelling charges which exploit advanced manufacture methods UNCLASSIFIED Resolution and complexity requirements Grain and charge designs Mechanical requirements Formulation requirements (Impetus, BR, etc.) Achievable/manufacturable geometries and properties Achievable formulations Product spec for IB simulation Product for laboratory and live ballistic testing Manufacture Research Component Research, develop and demonstrate additive propellant manufacture methods and formulations, and produce and characterise product in the laboratory Next Generation Gun Propelling Charges

16 Ballistics Research Stream UNCLASSIFIED Research Schedule Quantify theoretical gun performance improvements for highly progressive 3D grain geometries (Year 1) Develop methods for identifying and parametrising suitable novel 3D topologies, ready for optimisation (Years 1-2) Provide realistic, manufacturable, highperformance charge designs for manufacture and test (Years 2-4) Ballistic lab testing and analysis (Year 2-3) and live firing tests and demo (Year 4?) Tool Development Write a fast lumped parameter IB model for arbitrary grains (version 1 complete) Develop grain form functions to explore simple highly-progressive geometries (some initial geometries complete) Develop and implement multi-objective optimisation and/or a surface-area deconvolution method Code a form function model for arbitrary and complex 3D grains Develop suitable CV analysis methods Identify suitable gun testbed/s

17 Ballistics Research Stream UNCLASSIFIED Research Schedule Quantify theoretical gun performance improvements for highly progressive 3D grain geometries (Year 1) Develop methods for identifying and parametrising suitable novel 3D topologies, ready for optimisation (Years 1-2) Provide realistic, manufacturable, highperformance charge designs for manufacture and test (Years 2-4) Ballistic lab testing and analysis (Year 2-3) and live firing tests and demo (Year 4?) Tool Development Write a fast lumped parameter IB model for arbitrary grains (version 1 complete) Develop grain form functions to explore simple highly-progressive geometries (some initial geometries complete) Develop and implement multi-objective optimisation and/or a surface-area deconvolution method Code a form function model for arbitrary and complex 3D grains Develop suitable CV analysis methods Identify suitable gun testbed/s could equally be rocket or high explosive charge modelling

18 3D Printing Techniques UNCLASSIFIED Ref: Short Course From 3D Printing to Factory Floor, Massachussets Institute of Technology, Cambridge, MA, July 2016.

19 3D Printing Techniques UNCLASSIFIED Ref: Short Course From 3D Printing to Factory Floor, Massachussets Institute of Technology, Cambridge, MA, July 2016.

20 3D Printing Techniques: DST DLP UV Paste Ref: Short Course From 3D Printing to Factory Floor, Massachussets Institute of Technology, Cambridge, MA, July 2016.

21 3D Printing Techniques: Collaborative Partners SLA Binder Jet. FDM UV Paste Ref: Short Course From 3D Printing to Factory Floor, Massachusetts Institute of Technology, Cambridge, MA, July 2016.

22 DST 3D Printers for EM Evaluation UV Paste Extrusion: Hyrel 30M DLP: Gizimate 130 Basic Image from 3dprint.com Image from kudo3d.com

23 High-Solids Printing Challenges: DLP and UV Paste Printer Technology Challenge SLA/DLP and UV Paste High η and particle bridging affect reactive species mobility Solids-light interaction affect photoinitiator absorption SLA/DLP Particle induced light scattering affecting precision Solids-settling Effective layer re-coating UV Paste Liquid phase migration Achievable pressure drop for extrusion Maximum permissible particle size vs. precision Ref: Decker et al, Polymer, 2001, 42(13), Ref: Endruweit et al, Polymer Composites, 2006, 27(2),

24 High-Solids Printing Challenges (eg s) Solids - UV light interaction Liquid Phase Migration Feedstock Viscosity Print Precision Source: E. Caravaca, ARDEC (2016)

25 Transformative Energetics Conventional Energetic materials Processed by RAM High solids loaded conventional formulations Performance increase cf. conventional EM: +

26 Transformative Energetics Conventional Energetic materials Nano sizing Processed by RAM Nano energetic formulations Performance increase cf. conventional EM: ++

27 Transformative Energetics Conventional Energetic materials Nano sizing Processed by RAM Nano energetic formulations 3D printed nanoenergetic formulations Performance increase cf. conventional EM: > +++

28 Transformative Energetics Conventional Energetic materials Nano sizing Processed by RAM Nano energetic formulations 3D printed nanoenergetic formulations Performance increase cf. conventional EM: > +++ Benefits further augmented in volume limited and/or geometrically constrained applications

29 Transformative Energetics: Collaborative Partners Government Industry Academia

30 Transformative Energetics: A Pathway to Next Generation Munitions Merran Daniel, Andrew Hart, Arthur Provatas andrew.hart@dst.defence.gov.au Ph: UNCLASSIFIED