Details

Autor(en) / Beteiligte

• Feng, Rui
• Feng, Bojun
• Gao, Michael C.
• Zhang, Chuan
• Neuefeind, Joerg C.
• Poplawsky, Jonathan D.
• Ren, Yang
• An, Ke
• Widom, Michael
• Liaw, Peter K.

Titel

Superior High‐Temperature Strength in a Supersaturated Refractory High‐Entropy Alloy

Ist Teil von

• Advanced materials (Weinheim), 2021-12, Vol.33 (48), p.e2102401-n/a

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2021

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Refractory high‐entropy alloys (RHEAs) show promising applications at high temperatures. However, achieving high strengths at elevated temperatures above 1173K is still challenging due to heat softening. Using intrinsic material characteristics as the alloy‐design principles, a single‐phase body‐centered‐cubic (BCC) CrMoNbV RHEA with high‐temperature strengths (beyond 1000 MPa at 1273 K) is designed, superior to other reported RHEAs as well as conventional superalloys. The origin of the high‐temperature strength is revealed by in situ neutron scattering, transmission‐electron microscopy, and first‐principles calculations. The CrMoNbV's elevated‐temperature strength retention up to 1273 K arises from its large atomic‐size and elastic‐modulus mismatches, the insensitive temperature dependence of elastic constants, and the dominance of non‐screw character dislocations caused by the strong solute pinning, which makes the solid‐solution strengthening pronounced. The alloy‐design principles and the insights in this study pave the way to design RHEAs with outstanding high‐temperature strength. Structural materials with exceptional high‐temperature strengths are highly desirable for high‐temperature applications. In this work, three alloy‐design principles of the large atomic‐size and elastic‐modulus mismatches, the insensitive temperature‐dependence of elastic properties, and the dominance of non‐screw dislocations are used to design a CrMoNbV refractory high‐entropy alloy, which exhibits outperforming high‐temperature strengths.