Dynamic properties of FeCrMnNi, a high entropy alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 840; p. 142906
• Main Authors: Hawkins, M.C., Thomas, S., Hixson, R.S., Gigax, J., Li, N., Liu, C., Valdez, J.A., Fensin, S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 18.04.2022; Elsevier BV; Elsevier
• Subjects: Brittleness; Ductile fracture; Electron backscatter diffraction; Equation of state; Equations of state; Failure modes; Gas guns; High entropy alloys; MATERIALS SCIENCE; Mechanical properties; Photonic Doppler velocimetry; Post-impact metallurgical analysis; Shock loading; Strain analysis; Strain rate; High entropy alloys; Photonic Doppler velocimetry; Post-impact metallurgical analysis; Electron backscatter diffraction; Equation of state
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2022.142906

The goal of this paper was to assess the dynamic properties of a new class of materials, High entropy alloys (HEAs). Specifically, gas gun experiments coupled with recovery were performed on a specific HEA, FeCrMnNi, to measure its equation of state (EOS) and its spall strength, which is a measure of the stress required to nucleate voids under shock loading conditions. While there has been a plethora of work performed to assess the mechanical properties of these HEAs under uniaxial stress conditions as a function of strain rate, investigation of its properties in dynamic extremes remains rare. The current work fills this gap in knowledge for this novel class of materials. Our results show that the measured EOS for this material at one velocity was in reasonable agreement with an estimated Hugoniot. Furthermore, while the spall strength for this material was found to be ∼1.9 GPa, with some variation based on sample location, the main failure mode was brittle. This brittle failure leading to formation of cracks in the material is different than the ductile failure observed in pure iron and its alloys. DOE/NV/03624–1298.