Abstract: Near net shape refractory material is made in combustion driven compaction. The gas mixture is combusted, driving a piston or ram into a die containing refractory material powder, compressing the powder into a near net shape. As the chamber is filled with gas, the piston or ram is allowed to rest on the powder, pre-compressing the powder and removing trapped air. During compression, forces reach 150 tsi or more. Loading occurs within several hundred milliseconds. After compression, the shaped refractory part is sintered in a hydrogen environment. This process creates near net shape components with little scrap metal. The apparatus used to perform this process is about the size of a telephone booth and can be moved with a standard forklift. The powder may include a combination of Mo—Re, Re, W—Re, HfC and Hf of a fineness dictated by desired shrinkage, resulting in a material suitable for high-stress, high-temperature applications.

Abstract: A neo magnet is constructed by mixing a neo magnet powder with about 1% added two-part electrical insulating resin powder. The mixed powders are placed in a die and precompacted under about 20 tsi when filling a combustion chamber with a pressurized combustible gas and air mixture. The gas is ignited and rapidly drives a punch in to the die forming a solid magnet having a density of 6.1 g/cm3 or more. The solid magnet is heat treated to cure the resin and is coated with a polymer, zinc, aluminum or gold. Before precompacting a lubricated core rod in place in the die producing a thin-walled, neo ring magnet having a length to wall thickness aspect ratio.

Abstract: The new injection system provides rapid, high pressure, high density, and transient batch injection of cryogenic liquids. The system stores and maintains the temperature of liquids in vacuum jacketed tanks, increases pressures using pumps, and stores the high pressure fluid in accumulators. The accumulator periodically injects the fluids at high pressure in measured mass batches into a combustion chamber. The system injects enough liquid or gas in 0.5 to 3.0 seconds to provide 500 to 6500 psi in a closed chamber.

Abstract: A gas operated part forming die apparatus has compact high tonnage presses which are operated by high pressure gas generated within chambers and controlled to operate high pressure pistons and dies for compressing particulate material into dense formed parts. Combustion chambers are filled with pressurized mixtures of combustible gases and diluents. Elongated chambers have insulating walls and spaced electrodes. Some contain liquid or particulate ablatable materials or ablatable liners. Others extend fuzes between the electrodes and are filled with pressurized gases. Gas is removed from the particulate material. Die cavities may be precompressed during filing of chambers with pressurized gas. Igniting the combustible gases or creating arcs between the electrodes produces rapidly expanding high pressure resultant gases for driving pistons and movable dies and rapidly compressing die cavities. Pressures in the chambers are contained, or pistons are restrained until releasing and driving the pistons.

Abstract: A device for rapidly moving mechanically actuated devices, such as switches and valves with the capability of sub-millisecond response times being achievable with moving masses exceeding one kilogram. Response times approaching that of explosively actuated devices are obtained while retaining the repetitive cycling capability of non-explosively operated devices. Electrical energy stored in a capacitor pulses through electrodes and closed and open ends of a capillary tube to rapidly heat a gas and raise its pressure to a thousand atmospheres or more. The high pressure gas acts on a piston, accelerating it for a short distance before the pressure is vented around the piston to quickly reduce the drive force. The moving piston is brought to a stop by a hydraulic damping device. A reset device resets the piston, the capillary is refilled with working gas, and the capacitor is charged fro the next operation.

Abstract: A gas operated part forming die apparatus has compact high tonnage presses which are operated by high pressure gas generated within chambers and controlled to operate high pressure pistons and dies for compressing particulate material into dense formed parts. Combustion chambers are filled with pressurized mixtures of combustible gases and diluents. Elongated chambers have insulating walls and spaced electrodes. Some contain liquid or particulate ablatable materials or ablatable liners. Others extend fuzes between the electrodes and are filled with pressurized gases. Gas is removed from the particulate material. Die cavities may be precompressed during filing of chambers with pressurized gas. Igniting the combustible gases or creating arcs between the electrodes produces rapidly expanding high pressure resultant gases for driving pistons and movable dies and rapidly compressing die cavities. Pressures in the chambers are contained, or pistons are restrained until releasing and driving the pistons.

Abstract: A gas operated part forming die apparatus has compact high tonnage presses which are operated by high pressure gas generated within chambers and controlled to operate high pressure pistons and dies for compressing particulate material into dense formed parts. Combustion chambers are filled with pressurized mixtures of combustible gases and diluents. Elongated chambers have insulating walls and spaced electrodes. Some contain liquid or particulate ablatable materials or ablatable liners. Others extend fuzes between the electrodes and are filled with pressurized gases. Gas is removed from the particulate material. Die cavities may be precompressed during filing of chambers with pressurized gas. Igniting the combustible gases or creating arcs between the electrodes produces rapidly expanding high pressure resultant gases for driving pistons and movable dies and rapidly compressing die cavities. Pressures in the chambers are contained, or pistons are restrained until releasing and driving the pistons.

Abstract: A gas operated part forming die apparatus has compact high tonnage presses which are operated by high pressure gas generated within chambers and controlled to operate high pressure pistons and dies for compressing particulate material into dense formed parts. Combustion chambers are filled with pressurized mixtures of combustible gases and diluents. Elongated chambers have insulating walls and spaced electrodes. Some contain liquid or particulate ablatable materials or ablatable liners. Others extend fuzes between the electrodes and are filled with pressurized gases. Gas is removed from the particulate material. Die cavities may be precompressed during filing of chambers with pressurized gas. Igniting the combustible gases or creating arcs between the electrodes produces rapidly expanding high pressure resultant gases for driving pistons and movable dies and rapidly compressing die cavities. Pressures in the chambers are contained, or pistons are restrained until releasing and driving the pistons.

Abstract: A pulsed electrothermal powder spray apparatus and method increases coating particle velocities to the 2,000-4000 m/sec range. The apparatus includes a containment tube, which may be a reverse shock tube, having a capillary chamber section and a short barrel section. The tube is initially filled with an inert gas and powder is deposited in the barrel just downstream from the barrel's connection to the confined capillary discharge chamber. On receipt of a trigger signal, the muzzle shutter of the barrel section quickly opens, causing the inert gas to flow towards the open end of the barrel. A rarefaction wave propagates back up the barrel, towards the capillary chamber. Once the rarefaction wave reaches an electrode positioned at the front end of the capillary chamber, an arc discharge is triggered in the capillary, resulting in a quick rise in capillary temperature and pressure.

Abstract: Wire arc spraying using repetitively pulsed, high temperature gas jets, usually referred to as plasma jets, and generated by capillary discharges, substantially increases the velocity of atomized and entrained molten droplets. The quality of coatings produced is improved by increasing the velocity with which coating particles impact the coated surface. The effectiveness of wire-arc spraying is improved by replacing the usual atomizing air stream with a rapidly pulsed high velocity plasma jet. Pulsed power provides higher coating particle velocities leading to improved coatings. 50 micron aluminum droplets with velocities of 1500 m/s are produced. Pulsed plasma jet spraying provides the means to coat the insides of pipes, tubes, and engine block cylinders with very high velocity droplet impact.

Abstract: Paint is removed from bridges and structures by directing pulsed plasma jets at coatings on surfaces. The repetitively pulsed plasma jets ablate the coatings, and the resulting products are removed by reduced pressure in an enclosure. Plasma jets in an array are moved along a surface, with the jets overlapping. Power is controlled to remove the topcoats and one or more layers of topcoat without damaging an underlying primer coat, or to remove a primer coat to the bare surface. Jets in the array overlap to completely remove the coating. The pulsed plasma jets impact the surfaces directly in front of the plasma jets, and the gases flow outward, carrying ablated materials away from the surfaces. The enclosures have openings near the coated surface for allowing the inflow of ambient air into the reduced pressure enclosure to prevent escape of ablated products from the enclosure. The use of inert gas working fluid reduces formation of undesirable byproducts.

Abstract: Repetitively pulsed plasma jets generated by a capillary arc discharge at high stagnation pressure (>15,000 psi) and high temperature (>10,000 K) are utilized to produce 0.1-10 .mu.m sized metal powders and decrease cost of production. The plasma jets impact and atomize melt materials to form the fine powders. The melt can originate from a conventional melt stream or from a pulsed arc between two electrodes. Gas streams used in conventional gas atomization are replaced with much higher momentum flux plasma jets. Delivering strong incident shocks aids in primary disintegration of the molten material. A series of short duration, high pressure plasma pulses fragment the molten material. The pulses introduce sharp velocity gradients in the molten material which disintegrates into fine particles. The plasma pulses have peak pressures of approximately one kilobar. The high pressures improve the efficiency of disintegration. High gas flow velocities and pressures are achieved without reduction in gas density.

Abstract: A projectile is accelerated through a gun barrel in response to high pressure gas applied to the rear of the projectile in response to a high pressure plasma discharge. Plasma from the discharge flows transversely of the discharge into a chamber through multiple openings in a passage wall that confines the discharge. The high pressure, high temperature plasma flowing into the chamber causes an exothermic reaction of water and metal particles in a slurry in the chamber to produce high pressure hydrogen gas that flows longitudinally of the discharge against the rear of the projectile. To maintain the pressure of hydrogen gas acting against the projectile relatively constant as the projectile is accelerated down the barrel, electric power applied to the discharge increases substantially linearly as a function of time.

Abstract: A projectile is accelerated in a barrel bore by applying a plasma jet to a projectile propelling fluid. The plasma jet is derived from a structure forming a capillary passage having a wall formed by a low molecular weight, dielectric powdery filler or water in many rigid containers, shaped as spheres or straw-like tubes having axes parallel to the passage longitudinal axis. The fluid and jet interact so the fluid is heated by the jet, whereby low atomic weight constituents of the fluid are sufficiently heated to become mixed with the plasma to form a high pressure mixture that is injected into the bore to accelerate the projectile. The fluid is dragged into the plasma during mixing to cool the plasma and form a boundary layer between the plasma and the barrel walls so that the mixture does not cause substantial damage to the walls of the bore. The plasma is energized by applying voltage from an electric pulse source to electrodes at opposite ends of the passage.

Abstract: A projectile is accelerated through a gun barrel bore by a cartridge containing a high temperature, high pressure plasma jet source. The cartridge has a geometry enabling it to be loaded into a breech bore of the gun. The plasma jet is supplied to the rear of the projectile and is derived by a tube having an interior wall forming a capillary passage. A discharge voltage applied between spaced regions along the capillary passage ionizes a dielectric to form a plasma. First and second ends of the passage are respectively open and blocked to enable and prevent the flow of plasma through them. The blocked end closes the breech bore.