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Information × Registration Number 0220U104335, 0120U103598 , R & D reports Title Effect of Phase Transformations and Twinning on the low temperature mechanical properties of nanostructured Fe-Mn-Co-Cr High Entropy Alloys popup.stage_title Head Shumilin Sergii E., Кандидат фізико-математичних наук Registration Date 16-12-2020 Organization B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine popup.description2 A complex experimental researche of mechanical properties, low-temperature plastic deformation, and microstructure of high entropy alloys Fe40Mn40Co10Cr10 and Fe50Mn30Co10Cr10 in coarse-grained and nanostructured state have been carried out. It was found for coarse-grained HEA that the process of serrated deformation observed at the temperatures of 0.5-4.2 K becomes more complicated and non-uniform with the temperature decrease. A statistic analysis of low temperature serrated deformation was provided. The effect of the temperature and the structure on statistics of serrated deformation was established. It was found during acoustic investigation that in Fe50Mn30Co10Cr10 HEA a transition from initial state to deformed one leads to change of the character of dynamic Young’s modulus temperature dependence from nearly linear type to step type, and decreases its absolute values in all the investigated temperature range. Deformation curves σ(ε) were obtained during uniaxial compression of nanostructured HEA (with the average grain size of about 70 nm). High strength of the Fe40Mn40Co10Cr10 alloy HEA has been registered along with sufficient plasticity and HPT temperature effect on mechanical properties was established. It is found that nanostructured state obtained appears to be stable and the microhardness values don’t change during a year. Yield stress of the Fe40Mn40Co10Cr10 HEA in nanostructured state determined in the compression tests at 300 K becomes ~ 8 times higher than the same in coarse-grained state although plasticity becomes ~ 6 times lower, and the Fe50Mn30Co10Cr10 HEA lost its plastic properties.   Product Description popup.authors popup.nrat_date 2020-12-16 Close