Manufacturing & Prototyping

Low-Pressure Casting of Bulk Metallic Glasses for Gears and Other Applications

Applications include the automotive, aeronautics, aerospace, robotics, commercial, and military/defense industries. NASA’s Jet Propulsion Laboratory, Pasadena, California With the correct selection of composition, some bulk metallic glasses (BMGs) have been demonstrated that have excellent combinations of hardness, fracture toughness, and wear resistance so that their use in gears and gearboxes is a potentially commercially viable application. For BMGs to be used as a low-cost alternative to steel gears, rapid fabrication strategies are needed to cast the BMGs into net-shaped gears that require little or no post-casting machining prior to use. Die casting, suction casting, and other cold-mold casting techniques have been widely demonstrated for BMGs in the past, but the unique nature of gears precludes traditional techniques from being used in an optimal way.

Posted in: Briefs

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Aluminum Rocket Engine Injector Fabricated Using 3D Additive Manufacturing

Marshall Space Flight Center, Alabama Liquid rocket engine injectors can be extremely expensive to manufacture and hard to iterate to achieve high performance. Internal sealing points can also be the source of reliability issues. The technology disclosed here covers the application of a 3D additive manufacturing (AM) process to produce a functional aluminum injector for liquid propellant rocket engines, along with injector and overall engine design features that optimize the application of such processes to improve performance, reliability, and affordability relative to components produced using standard machining processes and designs. Aluminum was used for the injector instead of higher- temperature metals like stainless steel because its thermal conductance properties provide more opportunity to leverage the cooling potential of liquid oxygen and other cryogenic propellants.

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Making Flexible Ablators that are Flexible Char Formers

Ames Research Center, Moffett Field, California An approach was developed for making low-density, flexible ablators for a thermal protection system (TPS) from a flexible fibrous carbon substrate and a polymer resin. The material is foldable and stowable, and can be deployed in space without compromising performance. In addition, the material can be stowed in space for very long periods of time (years) without compromising deployability or performance. These flexible ablators offer an alternative to rigid TPS materials, thereby reducing design complexity and cost. On charring, the flexible ablative TPS retains its flexibility. After charring, the TPS has comparable flexibility and mechanical properties to the virgin material.

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Method for Providing Semiconductors Having Self-Aligned Ion Implant

Refined self-aligned ion implantation for improved SiC high-temperature transistors. John H. Glenn Research Center, Cleveland, Ohio This is a modification to technology for realizing durable and stable electrical functionality of high-temperature transistors. This modification is believed crucial to experimental implementation of SiC junction field effect transistors that electrically operated continuously at 500 °C for over 10,000 hours in an air ambient with less than 10% change in operational transistor parameters.

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Femtosecond Laser Processing of Metal and Plastics

Precision machining can be achieved with no thermal affects and minimal post-processing. Amada Miyachi America, Monrovia, California and Jenoptik, Jena, Germany While precise and fast, the down side to cutting with microsecond (ms) fiber lasers has been that the parts require a number of post-processing operations after they are cut, which add significantly to part cost, and can also damage mechanically delicate parts.

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Increased Alignment in Carbon Nanotube Growth

Ames Research Center, Moffett Field, California The combination of electronic and mechanical properties of carbon nanotubes (CNTs) has led to wide-ranging investigation of their potential in future electronics and computing, sensors, electrodes, and composites. A method and system for fabricating an array of two or more CNT structures on a coated substrate surface was developed.

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Process to Fabricate Specific Sized Monodisperse Polystyrene Microparticles

Langley Research Center, Hampton, Virginia A new method was developed to prepare monodisperse nano to microparticles of polystyrene ranging from 0.5 to 2.5 microns in relatively large-quantity batches (2 L, 10% by weight in water). Current commercial sources are very expensive and can typically only be acquired on a relatively small scale. Monodisperse polystyrene in this size range is an important component of laser velocimetry measurements in wind tunnels, but has many other potential uses. Polystyrene microparticles have uses in paints/coatings, adhesives, bio/immunoassays, reaction catalysts, and chromatography materials. The main benefits of this technology are low cost, scalability, and selectable size.

Posted in: Briefs, TSP

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