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Title: Chemistry-structure-property relations in Al10Cr15(Fe3Mn)75−x(Ni)x medium-entropy alloys
The microstructure, phase behavior, mechanical properties, and corrosion properties of a series of Al10Cr15(Fe3Mn)75−x(Ni)x medium-entropy alloys (MEAs) spanning 0–20 at% Ni were studied to elucidate the chemistry-structure-property relationship of this system as a function of Ni content. This work demonstrates that from an initial BCC phase Al10Cr15(Fe3Mn)75 MEA, Ni additions of 5 and 10 at% result in the formation of ordered B2-phase precipitates due to interaction of Ni with Al, resulting in high hardness (∼475 HV). Further Ni addition to 15 at% leads to a dual-phase FCC+BCC structure, with B2 phase precipitates distributed in the BCC matrix relatively rich in Al and Ni but depleted in Cr. This dual-phase structure has a high yield strength (YS) of 600 MPa with a total elongation of 15%. Additionally, the B2 precipitates in BCC phase serve as preferential sites for corrosion in 0.6 M NaCl. Increasing Ni content to 20 at% results in lower YS of 300 MPa, but a significant improvement in ductility and corrosion resistance due to the increased FCC phase fraction.  more » « less
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Journal of Alloys and Compounds
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Medium: X
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National Science Foundation
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