Three-dimensional (3D) printed fluoropolymer-based energetic compositions are made using 3D printing methods. The 3D printed fluoropolymer-based energetic compositions comprise a fluoropolymer and a reactive metal or metal oxide. The total weight percentage of the fluoropolymer and the reactive metal or metal oxide is 70-100% of the 3D printed fluoropolymer-based energetic composition, and the weight percentage of the reactive metal or metal oxide is 5-85 wt % of the total weight of the 3D printed fluoropolymer-based energetic material. The 3D printed fluoropolymer-based energetic material has a thickness of at least 200 μm.

A method of making a polysilylether (PSE) polymer includes: cooling a solution of diethylamine to 0° C. under argon; adding cold dialkyldichlorosilane to form a first mixture; slowly warming the first mixture to form dialkylbis(diethylamino)silane; diluting the first mixture with hexane then filtering via cannula; evaporating the hexane and excess diethylamine; purifying the dialkylbis(diethylamino)silane under vacuum distillation; adding the dialkylbis(diethylamino)silane to a solution of diol dissolved in tetrahydrofuran to form a second mixture; heating the second mixture to 60° C. while reflux condensing, and cooling and concentrating the second mixture under vacuum to form a resultant mixture containing the polysilylether (PSE) polymer.

A method for the manufacture of stable amorphous secondary explosives and combinations thereof—wherein the stability is enhanced with the addition of a polymeric additives and can be further enhanced with mechanical compression of the amorphous material.

A method of making a fuel grain for a hybrid rocket engine includes deposing beads of fuel grain material onto mandrel using additive manufacturing to form a cylindrical fuel grain, each bead including a polymer based rocket fuel material and a nanoscale metallic material. The deposing includes deposing multiple, adjacent beads to form concentric layers of beads, wherein a composition of the beads of the fuel grain material differs between the beads of a first layer and the beads of a second layer of the fuel grain.

An additively manufactured solid fuel grain for a hybrid rocket engine having a cylindrical shape, defining a center combustion port and comprising a stack of fused layers of polymeric material suitable for hybrid rocket fuel. Each layer is formed as a plurality of fused abutting concentric beads of solidified material arrayed around the center port. An oxidizer is introduced into the solid fuel grain through the center port, with combustion occurring along the exposed surface area of the solid fuel grain center port wall. Each concentric bead possesses a surface pattern that increases the combustion surface area and when stacked forms a rifling pattern of undulations that induces oxidizer-fuel gas axial flow to improve combustion efficiency. The port wall surface pattern persists during the rocket engine's operation as the fuel phase changes from solid to gas and is ablated.

A system is used for additively manufacturing propellant elements, such as for rocket motors, includes partially curing a propellant mixture before extruding or otherwise dispensing the material, such that the extruded propellant material is deposited on the element in a partially-cured state. The curing process for the partially-cured extruded material may be completed shortly after the material is put into place, for example by the material being heated at or above its cure temperature, such that it finishes curing before it fully cools. The propellant material may be prepared by first mixing together, a fuel, an oxidizer, and a binder, such as in an acoustic mixer. After that mixing a curative may be added to the mixture. The propellant mixture may then be directed to an extruder (or other dispenser), in which the mixture is heated to or above a cure temperature prior to the deposition, and then deposited.

A propellant manufacturing method for manufacturing a propellant including a propellant grain having a first surface on which combustion starts upon ignition and a second surface to be coupled to a wall surface that prevents combustion. The manufacturing method includes placing a portion of first propellant having a first burning rate in a first space containing a first position on the second surface; and placing a portion of second propellant having a second burning rate higher than the first burning rate in a second space containing a second position on the first propellant. The method further includes placing a portion of third propellant having a third burning rate higher than the second burning rate in a third space containing a third position on the first propellant. The method further includes completing the propellant grain by simultaneously hardening the entireties of the first propellant, the second propellant, and the third propellant.

The invention relates to Polymerisable Binders, and Insensitive Munition (IM) energetic materials particularly to non-phthalate IM propellant compositions which are printed by a UV curing additive layer manufacture process. invention there is provided an additive layer deposable energetic composition suitable for use as a propellant comprising the following components in the following relative proportions: component A; from 60% to 95% by weight of a highly energetic filler comprising at least one nitramine compound; and component B: from 5% to 20% by weight of a binder, wherein the binder contains component D a UV curable binder in the range of from 3% to 12% by total weight of the formulation, at least one UV photoinitiator, component C: from 1% to 15% of a plasticiser, the percentages by weight of components A, B, D and C, together with minor additives, if any, adding to 100%.

An apparatus with an anti-tamper architecture includes a substrate and a layer of a pyrotechnic composite arranged on a surface of the substrate. The pyrotechnic composite includes a metal and a metal oxide, and the layer has a thickness of about 1 micrometer to about 10 millimeters. A reaction of the pyrotechnic composite is an exothermic reaction and at least partially fractures the substrate after the reaction is initiated.

The invention is directed to a method for the preparation of an energetic material product such as a propellant or explosive charge or grain, wherein said method comprises additive manufacturing comprising co-extrusion of at least two materials to form a multi-layered filament and layer-by-layer deposition of said multi-layered filament, wherein said multi-layered filament comprises a first material layer and a second material layer of which at least one comprises an energetic material. In another aspect, the invention is directed to an apparatus for use in this method, said apparatus comprising a co-extrusion nozzle