Materials & Coatings

Aircraft Wings Change Shape in Flight

The EU project SARISTU (Smart Intelligent Aircraft Structures) aims to reduce kerosene consumption by six percent, and integrating flexible landing devices into aircraft wings is one step towards that target. A new mechanism alters the landing flap’s shape to dynamically accommodate the airflow. Algorithms to control the required shape modifications in flight were programmed by the Fraunhofer Institute for Electronic Nano Systems ENAS in Chemnitz, in collaboration with colleagues from the Italian Aerospace Research Center (CIRA) and the University of Naples."We’ve come up with a silicon skin with alternate rigid and soft zones,” Said Andreas Lühring from Fraunhofer IFAM. “There are five hard and three soft zones, enclosed within a silicon skin cover extending over the top.”The mechanism sits underneath the soft zones, the areas that are most distended. While the novel design is noteworthy, it is the material itself that stands out, since the flexible parts are made of elastomeric foam that retains their elasticity even at temperatures ranging from -55 to 80° Celsius.Four 90-centimeter-long prototypes — two of which feature skin segments — are already undergoing testing.SourceAlso: Learn about Active Wing Shaping Control.

Posted in: News, Aviation

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Metal Injection Molding Turns the Volume Up, and Down

When increased quantities of metal parts are needed, metal injection molding (MIM) is often a logical next step. Our free MIM white paper covers the multi-step process involved in molding metal parts, detailed technical specs needed for design, commonly used materials and a comparison to other metal-forming technologies like direct metal laser sintering and die casting.

Posted in: White Papers

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Liquid Silicone Rubber Takes the Heat

Our comprehensive white paper on liquid silicone rubber provides a detailed look at the injection-molding process and offers guidelines to achieve better molded LSR parts. While there are some shared similarities to thermoplastic injection molding, LSR is a thermoset material with a unique set of design characteristics.

Posted in: White Papers

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Elevated-Temperature, Highly Emissive Coating for Energy Dissipation of Large Surfaces

This coating can be used in high-temperature rocket nozzles, control surfaces, industrial furnaces, and transfer lines. Marshall Space Flight Center, Alabama This coating demonstrates high emittance above 80% or better at broad wavelengths within the infrared spectrum. It has shown to have an extremely stable emittance at lower wavelengths within the infrared (IR) spectrum, where energy dissipation is critical at elevated temperatures. The coating has demonstrated increases in surface texturing, and ultimately an increase in emissivity when exposed to temperatures up to 2,050 °F (≈1,120 °C). It is also stable at continuous run, elevated temperatures, and shows no signs of spalling or erosion.

Posted in: Coatings & Adhesives, Materials, Briefs

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Catalyst for Treatment and Control of Post-Combustion Emissions

This oxidation/reduction catalyst can be used in diesel and natural gas applications, and in nonautomotive pollution sources. Langley Research Center, Hampton, Virginia Emissions from fossil-fuel combustion contribute significantly to smog, acid rain, and global warming problems, and are subject to stringent environmental regulations. These regulations are expected to become more stringent as state and regional authorities become more involved in addressing these environmental problems. Better systems are needed for catalytic control.

Posted in: Coatings & Adhesives, Materials, Briefs, TSP

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Thermally Activated Crack Healing Mechanism for Metallic Materials

A thin metallic film of a low-melting-temperature healing agent is used. Langley Research Center, Hampton, Virginia A thermally activated healing mechanism is proposed and experimentally validated to mitigate crack propagation damage in metallic materials. The protected structure is coated with a thin metallic film of a low-melting-temperature healing agent. To heal or mitigate crack damage, the structure is heated to the melting temperature of the healing agent, allowing it to flow into the crack opening. Once in the crack mouth, the healing agent has two benefits: (1) by adhering to the crack surfaces, the healing agent bridges the crack, reducing the amount of load at the crack tip; and (2) any voluminous substance in the crack mouth causes crack closure (premature crack-face contact during cyclic loading) that also reduces the crack-tip loading.

Posted in: Coatings & Adhesives, Materials, Briefs, TSP

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Subsurface Imaging of Nanocomposites

Applications include sensors and actuators, aerospace structures, and tissue infusion in medical areas. Langley Research Center, Hampton, Virginia A nondestructive method that is based on modified atomic force ultrasonic microscopy (AFUM) methods has been developed for characterizing nanomaterials. The technology allows imaging and quantifying of material properties at the surface and subsurface levels. The technology reveals the orientation of nanotubes within a composite structure and offers the ability to determine subsurface characteristics without destroying the nanomaterial structure. The method is widely applicable for basic nanomaterials characterization, including distribution and orientation of particles in a nanocomposite, localized elastic constants and changes in elastic constants, adhesive surface properties, sound velocity, and material damping coefficient.

Posted in: Coatings & Adhesives, Materials, Briefs

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