Researchers from Tohoku Universitys Graduate School of Engineering have discovered a novel iron-based superelastic alloy (SEA) capable of withstanding extreme temperaturesboth high and low. A paper on the work is published in Science.<\/p>\n
SEAs are found in a wide variety of commercial applications because of their superelasticity, allowing them to regain their original shape. Superelasticity occurs when the metal undergoes deformation at the point known as critical stress.<\/p>\n
Generally, SEAs have a positive temperature dependence; the critical stress increases as the temperature rises. Conventional metal-based SEAs such as Ti-Ni cannot be used at temperatures lower than -20 C or higher than 80 C and are costly to make. This limits their application to the form of thin wires or tubes.<\/p>\n
Associate Professor at Tohoku University, Toshihiro Omori and his team developed an iron-based SEA system, known as Fe-Mn-Al-Cr-Ni. This cost-effective SEA can operate at a much wider temperature range.<\/p>\n<\/p>\n
A comparison of the stress-strain curves of the new iron-based SEA in comparison to Nickel-Titanium alloy. Credit: Tohoku University<\/p>\n
A significant advantage of the new SEA is its controllable temperature-dependence. Increasing the amount of Chromium allowed the researchers to change the temperature dependence from a positive to a negative. Balancing the Chromium content resulted in zero temperature dependence with the critical stress remaining almost constant at various temperatures.<\/p>\n
The discovery possesses wide-spread application for outer-space exploration given the large temperature fluctuations that occur, said Professor Omori. <\/p>\n
Omori points to NASAs work on a superelastic tire that can withstand excessive deformation for Moon and Mars missions. The temperature differences between night and day on the Moon and Mars are -170 C to 120 C and -150 C to 20 C respectively.<\/p>\n
Resources<\/p>\n
Ji Xia, Yuki Noguchi, Xiao Xu, Takumi Odaira, Yuta Kimura, Makoto Nagasako, Toshihiro Omori, Ryosuke Kainuma (2020) Iron-based superelastic alloys with near-constant critical stress temperature dependence Science doi: 10.1126\/science.abc1590<\/p>\n
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New iron-based superelastic alloy capable of withstanding extreme temperatures - Green Car Congress<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" Researchers from Tohoku Universitys Graduate School of Engineering have discovered a novel iron-based superelastic alloy (SEA) capable of withstanding extreme temperaturesboth high and low. A paper on the work is published in Science. SEAs are found in a wide variety of commercial applications because of their superelasticity, allowing them to regain their original shape Continue reading