The effect of interstitial carbon on the mechanical properties and dislocation substructure evolution in Fe<sub>40.4</sub>Ni<sub>11.3</sub>Mn<sub>34.8</sub>Al<sub>7.5</sub>Cr<sub>6</sub> high entropy alloys [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Science, 2016. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- pages 228-239 : digital, PDF file
- Additional Creators:
- Oak Ridge National Laboratory, United States. Department of Energy. Office of Science, and United States. Department of Energy. Office of Scientific and Technical Information
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- Free-to-read Unrestricted online access
- A systematic study of the effects of up to 1.1 at. % carbon on the mechanical properties and evolution of the dislocation substructure in a series of a high entropy alloys (HEA) based on Fe<sub>40.4</sub>Ni<sub>11.3</sub>Mn<sub>34.8</sub>Al<sub>7.5</sub>Cr<sub>6</sub> is presented. Transmission electron microscopy (TEM), synchrotron X-ray diffraction (XRD) and atom probe tomography (APT) were used to show that all the alloys are single-phase f.c.c. random solid solutions. The lattice constant, determined from synchrotron XRD measurements, increases linearly with increasing carbon concentration, which leads to a linear relationship between the yield strength and the carbon concentration. The dislocation substructures, as determined by a TEM, show a transition from wavy slip to planar slip and, at higher strains, and from cell-forming structure (dislocations cells, cell blocks and dense dislocation walls) to non-cell forming structure (Taylor lattice, microbands and domain boundaries) with the addition of carbon, features related to the increase in lattice friction stress. The stacking fault energy (measured via weak-beam imaging of the separation of dislocation partials) decreases with increasing carbon content, which also contributes to the transition from wavy slip to planar slip. The formation of non-cell forming structure induced by carbon leads to a high degree of strain hardening and a substantial increase in the ultimate tensile strength. In conclusion, the consequent postponement of necking due to the high strain hardening, along with the plasticity accommodation arising from the formation of microbands and domain boundaries, result in an increase of ductility due to the carbon addition.
- Published through SciTech Connect., 09/01/2016., "KC0403040", "ERKCZ01", Acta Materialia 120 C ISSN 1359-6454 AM, and Zhangwei Wang; Ian Baker; Zhonghou Cai; Si Chen; Jonathan D. Poplawsky; Wei Guo.
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