|About this Abstract
|Materials Science & Technology 2020
|High Entropy Materials: Concentrated Solid Solution, Intermetallics, Ceramics, Functional Materials and Beyond
|Lattice-distortion-enhanced-yield Strength in a Refractory High-entropy Alloy
|Chanho Lee, Yi Chou, George Kim, Michael C. Gao, Ke An, Chuan Zhang, Wei Chen, Jonathan D. Poplawsky, Gian Song, Yi-Chia Chou, Peter K. Liaw
|On-Site Speaker (Planned)
|Peter K. Liaw
Severe lattice distortion is one of the four core effects proposed in single-phase high-entropy alloys (HEAs) and contributes significantly to the yield strength. However, the connection between the atomic-scale lattice distortion and macro-scale mechanical properties through experimental verifications has yet to be fully achieved, owing to two critical challenges: (1) the difficulty in the development of homogeneous single-phase solid-solution HEAs, and (2) the ambiguity in describing the lattice distortion and related measurements and calculations. We have designed and developed the single-phase body-centered-cubic (BCC) refractory HEA, NbTaTiVZr, using thermodynamic modeling coupled with experimental verifications. Compared to our previously-developed single-phase NbTaTiV HEA, the NbTaTiVZr refractory HEA shows a higher yield strength without significant change in the microstructures after the addition of the Zr element. The increase in yield strength is systematically and quantitatively studied in terms of lattice distortion using a theoretical model, first-principles calculations, and experimental verifications.