Effect of Mo on high-temperature strength of refractory complex concentrated alloys: A perspective of electronegativity difference
Journal article, 2022

Refractory complex concentrated alloys, RCCAs, show great potential for ultrahigh-temperature applications. High-temperature strength is one of the key requirements for RCCAs to qualify for that purpose. Some RCCAs already show superior high-temperature strength than that of commercial Ni-based superalloys, but many other RCCAs do not. It is thus important to identify the key factors that control the high-temperature strength of RCCAs. In this work, based on a statistic analysis of the yield strength at 1000 °C (σy1000) for 55 reported RCCAs, interestingly, it is revealed that Mo-containing RCCAs have in general a higher σy1000 than those RCCAs not containing Mo. The effect of Mo is attributed to its larger electronegativity and hence the larger electronegativity difference to other alloying elements, rather than to its higher melting point. The previously established proposal that a large electronegativity difference favoring the charge transfer and creating an atomic-level pressure that contributes to the strengthening of RCCAs at room temperature, seems effective even at a high temperature of 1000 °C. In addition, the large electronegativity difference also favors the room-temperature strength of single-bcc-phase RCCAs. The findings from this work, further verified experimentally in six new RCCAs, shed light on new research directions to develop RCCAs with decent strength at both high temperatures and room temperature, using a simple descriptor on the electronegativity difference.

High temperature strength

High entropy alloys

Melting point

Electronegativity

Refractory complex concentrated alloys

Author

Q. Hu

Jiangxi Academy of Sciences

Sheng Guo

Chalmers, Industrial and Materials Science, Materials and manufacture

J. L. Guo

Jiangxi Academy of Sciences

F. F. Luo

Jiangxi Academy of Sciences

J. W. Wang

Jiangxi Academy of Sciences

Journal of Alloys and Compounds

0925-8388 (ISSN)

Vol. 906 164186

Subject Categories

Other Materials Engineering

Metallurgy and Metallic Materials

Condensed Matter Physics

DOI

10.1016/j.jallcom.2022.164186

More information

Latest update

3/3/2022 3