High Temperature Property of AlCrFeNi Multi-principal Element High Entropy Alloy

The AlCrFeNi multi-principal element alloy was prepared using vacuum smelting method. Then the microstructure of alloy after casting and different heat treatments was studied through optical microscopy, X-ray diffraction, scanning electron microscopy. And high temperature tensile test and high temperature creep test for the alloy were performed. The results show the cast alloy was consisted of a white α-(Cr,Fe) phase and gray NiAl phase, showing eutectic structure with BCC structure. And its hardness was 411.3 HV. With the heat treatment temperature (900-1 200 ℃) increasing, there was no change of two-phase structure of the alloy, but grains grew up slightly, so this alloy had better structure stability at high temperature. At 700 ℃ both high temperature short time tensile and creep fractures of the alloy displayed a mixing characteristic of intergranular fracture and ductile fracture. The alloy had good plasticity, whose tensile elongation and area reduction rate were 30.6%, 41.0%, respectively.