Influence of gradual replacement of aluminum for copper in FeCrCoNiCu alloys

Abstract

AbstractAlxFeCrCoNiCu1‐x alloys with multiprincipal elements (x values in a molar ratio of 0, 0.2, 0.4, 0.6, 0.8, 1) are prepared by arc melting. When part of copper in the alloy began to be substituted by aluminum, although the microstructure is still the face centered cubic structure, the hardness of the alloy has drastically decreased. With the increase of replacing copper with aluminum, the hardness of alloy increases slowly, and when x = 0.8, rich aluminum nanoparticle precipitation and “Widmanstatten side plates” appear in the alloy, and the hardness of the alloy is increasing greatly. Finally, when the copper is completely replaced by aluminum, the alloy becomes body centered cubic structure, and the hardness reaches the maximum. In terms of ductility, x = 0∼0.6, alloys exhibit the good ductility, and no fracture occurs within the compression range, but the yield strength is relatively low. When x = 0.8∼1, the ductility of the alloy decreases obviously, and the cleavage fracture appears in the compression range, but the yield strength is greatly improved. Among these alloys, it can be found that these mechanical changes are closely related to changes in microstructure.