A high-entropy alloy with hierarchical nanoprecipitates and ultrahigh strength. Academic Article uri icon

abstract

  • High-entropy alloys (HEAs) are a class of metallic materials that have revolutionized alloy design. They are known for their high compressive strengths, often greater than 1 GPa; however, the tensile strengths of most reported HEAs are limited. Here, we report a strategy for the design and fabrication of HEAs that can achieve ultrahigh tensile strengths. The proposed strategy involves the introduction of a high density of hierarchical intragranular nanoprecipitates. To establish the validity of this strategy, we designed and fabricated a bulk Fe25Co25Ni25Al10Ti15 HEA to consist of a principal face-centered cubic (fcc) phase containing hierarchical intragranular nanoprecipitates. Our results show that precipitation strengthening, as one of the main strengthening mechanisms, contributes to a tensile yield strength (0.2) of ~1.86 GPa and an ultimate tensile strength of ~2.52 GPa at room temperature, which heretofore represents the highest strength reported for an HEA with an appreciable failure strain of ~5.2%.

published proceedings

  • Sci Adv

author list (cited authors)

  • Fu, Z., Jiang, L., Wardini, J. L., MacDonald, B. E., Wen, H., Xiong, W., ... Lavernia, E. J.

complete list of authors

  • Fu, Zhiqiang||Jiang, Lin||Wardini, Jenna L||MacDonald, Benjamin E||Wen, Haiming||Xiong, Wei||Zhang, Dalong||Zhou, Yizhang||Rupert, Timothy J||Chen, Weiping||Lavernia, Enrique J

publication date

  • October 2018