The tensile property and notch sensitivity of AlCoCrFeNi2.1 high entropy alloy with a novel “steel-frame” eutectic microstructure

Abstract AlCoCrFeNi2.1 high entropy alloy with a novel “steel-frame” eutectic microstructure was prepared and its microstructure, mechanical properties, and notch sensitivity were characterized. The alloy exhibits high strength and high ductility due to the unique steel framed eutectic microstructure that consists of face-centered-cubic (FCC) phase, L12 phase and B2 phase. This unique eutectic microstructure hinders dislocation movements and postpones the crack propagation. Considering the notch sensitivity of materials is critical to its application, U-shaped notches with four different notch radii were introduced to investigate the notch sensitivity and their effects on the deformation behavior. The results show that AlCoCrFeNi2.1 alloy is insensitive to the notch and the tensile properties of the notched specimens are improved compared to that of the un-notched counterpart.