Microstructure and Tensile Behavior of Al8Co17Cr17Cu8Fe17Ni33 (at.%) High-Entropy Alloy

Microstructure evolution and tensile behavior of the high-entropy alloy Al8Co17Cr17Cu8Fe17Ni33 (at.%) are investigated at room temperature and at 500A degrees C in the as-cast state and under different heat-treatment conditions. Detailed microstructural characterizations are carried out using optical microscopy, scanning electron microscopy, and transmission electron microscopy. The equilibrium phase evolution as a function of temperature was calculated using the Thermo-Calc software (Thermo-Calc Software, Stockholm, Sweden) integrated with TTNi-7 database. The observed majority phase is a face-centered cubic solid solution for all tested specimens. Tensile ductility at room temperature and at elevated temperature is enhanced by heat treatment at 1150A degrees C. An embrittlement phenomenon has been observed after a heat treatment at 700A degrees C resulting in significant degradation in tensile properties.