Design and Semisolid Processing of High-Entropy Alloys Based on the CrCuFeMnNi System

Abstract

Semisolid processing of alloys comprises a whole class of technological processes that exploits the thixotropic behavior exhibited by metals with globular microstructure. Thixoforming is one of them and involves partial melting of a raw material before the forming step. It offers many advantages over conventional manufacturing processes, such as less turbulence during mold filling, reduced porosity, lower contraction during solidification, lower working temperatures, lower forming loads and the possibility of producing complex-shaped components. Despite these significant advantages, thixoforming is still limited in industry due to the lack of alloys amenable to the process, which explains the effort for the development of brand new compositions or even the modification of existing ones. In this context, high-entropy alloys have become a new source of exploitation. Such alloys consist of solid solutions composed of multiple principal alloying elements. Based on this, an ideal high entropy alloy would be that presenting at least two solid solutions with discrepant melting points, leading to the formation of a solidification interval. Therefore, the objective of this project is to develop high-entropy alloys specifically designed for thixoforming. Such a goal will be achieved by selecting suitable Cu contents in CrCuxFeMnNi alloys and, thus, by studying the microstructural evolution and deformation behavior of these alloys in the semisolid state. Lastly, the mechanical properties of thixoformed samples will be determined.