A Sequence of Phase Transformations and Phases in NiCoFeCrGa High Entropy Alloy
Ádám Vida,
János Lábár,
Zoltán Dankházi,
Zsolt Maksa,
Dávid Molnár,
Lajos K. Varga,
Szilvia Kalácska,
Márk Windisch,
Gabriella Huhn,
Nguyen Q. Chinh
Affiliations
Ádám Vida
Department of Industrial Materials Technology, Bay Zoltán Nonprofit Ltd. for Applied Research, Kondorfa u.1., H-1116 Budapest, Hungary
János Lábár
Department of Materials Physics, Eötvös Loránd University, P.O.B. 32, H-1518 Budapest, Hungary
Zoltán Dankházi
Department of Materials Physics, Eötvös Loránd University, P.O.B. 32, H-1518 Budapest, Hungary
Zsolt Maksa
Department of Materials Physics, Eötvös Loránd University, P.O.B. 32, H-1518 Budapest, Hungary
Dávid Molnár
Materials Science Group, Dalarna University, SE-791-88 Falun, Sweden
Lajos K. Varga
Institute of Solid State Physics and Optics, Wigner Research Center for Physics, H-1121 Budapest, Konkoly-Thege u. 29-33, Hungary
Szilvia Kalácska
Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory of Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, 3602 Thun, Switzerland
Márk Windisch
Department of Industrial Materials Technology, Bay Zoltán Nonprofit Ltd. for Applied Research, Kondorfa u.1., H-1116 Budapest, Hungary
Gabriella Huhn
Department of Materials Physics, Eötvös Loránd University, P.O.B. 32, H-1518 Budapest, Hungary
Nguyen Q. Chinh
Department of Materials Physics, Eötvös Loránd University, P.O.B. 32, H-1518 Budapest, Hungary
The present investigation is directed to phase transitions in the equimolar NiCoFeCrGa high entropy alloy, which is a mixture of face-centered cubic (FCC) and body-centered cubic (BCC) crystalline phases. The microstructure of the samples was investigated by using scanning electron microscopy (SEM), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), transmission electron microscopy-based energy-dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS), as well as X-ray diffraction (XRD) measurements. Based on the phases observed in different temperature ranges, a sequence of the phase transitions can be established, showing that in a realistic process, when freely cooling the sample with the furnace from high to room temperature, a microstructure having spinodal-like decomposition can also be expected. The elemental mapping and magnetic behaviors of this decomposed structure are also studied.
