Abstract
Despite the decade-long worldwide interest in refractory high-entropy alloys (RHEAs) for high-temperature applications, their tensile creep properties have not been published, making it difficult to assess their true potential. Here, we report the tensile creep behavior at 980°C and 1,100°C of TiZrHfNbTa, a body-centered cubic (BCC), solid solution RHEA, and compare it with single crystals of a leading precipitate-strengthened Ni-base superalloy, CMSX-4, as well as its solid solution matrix. The superalloy is 25 times stronger in creep than the RHEA at 980°C and 70 times stronger at 1,100°C. Even the single-phase matrix of CMSX-4 has three times the creep strength of the RHEA at 980°C. We also find that the microstructure of the RHEA is unstable and undergoes phase decomposition during creep. In light of these observations, we discuss the temperature ranges where RHEAs may or may not be competitive with Ni-base superalloys.
| Original language | English |
|---|---|
| Article number | 100991 |
| Journal | Cell Reports Physical Science |
| Volume | 3 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 17 2022 |
Funding
This research was primarily supported by the U.S. Department of Energy , Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division (to Y.Y. and E.P.G.). Additional support from German Research Foundation (DFG) project GL 181/56-1 within the priority program SPP2006 “Compositionally Complex Alloys—High Entropy Alloys (CCA-HEA)” is acknowledged (to C.G and U.G.).
Keywords
- Ni-base superalloys
- creep
- high-temperature materials
- phase instability
- refractory high-entropy alloys
- solid solutions