Aerospace and Defense applications require specialized thermal management materials to perform unique and demanding tasks. These may include requirements for high-temperature performance, high heat spreading, repeated flexibility, long life in a vacuum environment, being lightweight, and having ultra-low outgassing. Flexible graphite heat spreaders and thermal interface materials are uniquely designed with these vital requirements in mind.
Spacecraft and Satellite Applications
Thermal Straps
In spacecraft applications, heat must often be transferred from one part of the craft to another. A thermal strap is the easiest way to do this. In a thermal strap, multiple layers (usually 10 – 50) of thin, flexible graphite are stacked in a long strip with the ends bolted to the body of the spacecraft. The graphite thermal strap is a robust, permanent thermal solution with a lightweight form factor. Graphite thermal straps do not generate foreign object debris (FOD), which can damage the satellite during launch. The graphite does not outgas anything that can coat optical lenses or foul delicate sensors.
Thermal Interface Materials
Bare metal-to-metal contact is inefficient for moving heat from a hot surface to a heat sink. This is especially true in a vacuum application, where the micro gaps between the two metal surfaces act as an effective thermal insulation barrier. To solve this problem, thermal interface material is used. However, there are several additional requirements for spacecraft. The material must be lightweight, permanent, and cannot outgas anything that could coat optical lenses or interfere with sensors. HiTherm™ thermal interface material meets all of these demanding requirements. Already listed on the NASA outgassing database and in use in hundreds of satellites, including the Hubble Space Telescope and the International Space Station, HiTherm thermal interface material is the number one choice for all types of spacecraft.
Thermal Radiators
Excessive heat is generated on many types of spacecraft. This “waste heat” can interfere with the efficient operation of sensitive electronics, optics, and sensors. The most effective way to eliminate this waste heat is to first spread the heat from the heat generator to a large, heated surface and then shed it to space by the mechanism of thermal radiation. To spread the heat, large sheets of flexible graphite are used. Graphite is not only the best heat spreader available, but it is flexible and lightweight, allowing it to be rolled for launch and then unrolled once the spacecraft is in orbit. It can be coated to increase thermal radiation emissivity (Ɛ) to ≥ 0.9. Graphite is a permanent heat spreader that will not outgas, dry out, or wear out. It remains flexible and won’t generate foreign object debris (FOD) during launch.
Featured NeoGraf Solutions Products:
eVTOL, eSTOL, and eCTOL Aircraft and Drones
Battery-powered aircraft and drones have unique requirements to ensure that the batteries used in these vehicles perform to their highest capabilities yet do not pose a safety hazard to passengers or equipment. The biggest issue when dealing with aviation batteries has to do with heat. Charging, discharging, or even normal flight operations can produce heat in amounts that will cause hot spots in the cells. This uneven distribution of heat results in the shortening of useful cell lifetime or, in extreme cases, can lead to a cascading failure where every cell in a module catches fire in a thermal propagation event, also known as thermal runaway. Flexible graphite heat spreaders efficiently eliminate hot spots from the cells and then spread them to an outside heat sink. Building on a long and successful history in the EV and maritime industries, flexible graphite is a lightweight, thin, and permanent thermal solution. GraFoil® graphite gaskets efficiently seal battery modules to prevent the escape of hot gases while remaining flexible and reusable.
