Development of a Refractory High Entropy Superalloy
1
Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, OH 45433, USA
2
Department of Materials Science and Engineering and Northwestern University Center for Atom-Probe Tomography, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA
*
Author to whom correspondence should be addressed.
Academic Editor: An-Chou Yeh
Entropy 2016, 18(3), 102; https://doi.org/10.3390/e18030102
Received: 12 February 2016
/
Revised: 2 March 2016
/
Accepted: 2 March 2016
/
Published: 17 March 2016
(This article belongs to the Special Issue High-Entropy Alloys and High-Entropy-Related Materials)
Microstructure, phase composition and mechanical properties of a refractory high entropy superalloy, AlMo0.5NbTa0.5TiZr, are reported in this work. The alloy consists of a nano-scale mixture of two phases produced by the decomposition from a high temperature body-centered cubic (BCC) phase. The first phase is present in the form of cuboidal-shaped nano-precipitates aligned in rows along <100>-type directions, has a disordered BCC crystal structure with the lattice parameter a1 = 326.9 ± 0.5 pm and is rich in Mo, Nb and Ta. The second phase is present in the form of channels between the cuboidal nano-precipitates, has an ordered B2 crystal structure with the lattice parameter a2 = 330.4 ± 0.5 pm and is rich in Al, Ti and Zr. Both phases are coherent and have the same crystallographic orientation within the former grains. The formation of this modulated nano-phase structure is discussed in the framework of nucleation-and-growth and spinodal decomposition mechanisms. The yield strength of this refractory high entropy superalloy is superior to the yield strength of Ni-based superalloys in the temperature range of 20 °C to 1200 °C.
View Full-Text
Keywords:
refractory high entropy alloy; superalloy; microstructure and phase analysis; mechanical properties
▼
Show Figures
Figure 1
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
MDPI and ACS Style
Senkov, O.N.; Isheim, D.; Seidman, D.N.; Pilchak, A.L. Development of a Refractory High Entropy Superalloy. Entropy 2016, 18, 102. https://doi.org/10.3390/e18030102
AMA Style
Senkov ON, Isheim D, Seidman DN, Pilchak AL. Development of a Refractory High Entropy Superalloy. Entropy. 2016; 18(3):102. https://doi.org/10.3390/e18030102
Chicago/Turabian StyleSenkov, Oleg N., Dieter Isheim, David N. Seidman, and Adam L. Pilchak. 2016. "Development of a Refractory High Entropy Superalloy" Entropy 18, no. 3: 102. https://doi.org/10.3390/e18030102
Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
