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Bulk Metallic Glass

By David Broome, David Xao, Eric Timmons, and George Vithoulkas This video concerns bulk metallic glass (BMG) and its use as gears in space-destined robots. The challenge with BMG is the cooling process - in order to produce an amorphous microstructure in metals, very rapid cooling must be obtained. This cooling tends to be on the order of thousands of degrees Celsius a second, something that can only be done using specialized instrumentation. The metallic glass that is produced as a result shares many of the properties of glass, including the ability to be blow-molded due to low temperatures. Injection-molding is also a benefit of having a relatively low melting temperature. BMG also doesn’t become brittle at low temperatures and gears made out of the material do not need lubrication; a huge advantage in terms of low-temperature space-travel. Their manufacture is also less expensive. As a whole, BMG offers a hefty set of advantages for the future engineering of space-intended robots. As with the production of any advanced material, there are a set of challenges specific to this type of technology. Some challenges specific to BMG include: (1) the production process, (2) obtaining the equipment needed to produce BMG, and (3) ensuring that BMG production is consistent and accurate enough to meet the constraints of mechanical gears. As stated above, BMG needs a very rapid cooling process to form. This cannot be obtained naturally, and relies upon tight regulation and observation of the necessary process. Obtaining essential equipment also plays into this idea. Since highly-advanced technology is required, BMG production would require a substantial investment into gaining the proper equipment prior to starting production. Finally, BMG gears need to be produced with a high level and precision to function correctly and without resulting in erosion of the gears themselves or other parts. The potential for injection-molding of BMG circumvents this somewhat, but still mandates careful observation and formation of molds. Works Cited Pictures: https://www.hindawi.com/journals/jma/... http://www.machinedesign.com/sites/ma... http://www.techbriefs.com/images/stor... http://www.pacificgolfclubs.com/custo... http://www.retailtheftprevention.com/... https://en.wikipedia.org/wiki/Rover_(...) Articles: Greicius, T. (2016, November 28). Metallic Glass Gears Make for Graceful Robots. Retrieved May 10, 2017, from https://www.nasa.gov/feature/jpl/meta... NASA. (n.d.). Space Technology: Game Changing Development - Bulk Metallic Glass Gears. Retrieved May 10, 2017, from https://gameon.nasa.gov/gcd/files/201... Nieh, T. G., Hirotsu, Y., Ohkubo, T., Liu, C. T., & Wadsworth, J. (2001, September 3). Plasticity and structural instability in a bulk metallic glass deformed in the supercooled liquid region. Retrieved May 10, 2017, from http://www.sciencedirect.com/science/... Petranek, S. (2017, January 02). One Giant Leap for Private Space Exploration. Retrieved May 10, 2017, from https://dailyreckoning.com/one-giant-...