In-house synthesis of CoCrFeNi ingots using an electric furnace

Abstract

• Ingots of Multi-Principal Element Alloys is mostly obtained by casting using special equipment. • Melting and natural cooling of prealloyed powders in an electric furnace is a valid alternative. • A necessary requisite for adopting this static synthesis method is lack of liquid phase separation. • The proof-of-concept material was an equimolar CoCrFeNi alloy. • Microsegregation due to solute partitioning was mitigated through annealing. Bulk Multi-Principal Element Alloys (MPEAs) are generally synthesized by casting, a process needing specific equipment. Here, a standard laboratory electric furnace was used to synthesize bulk CoCrFeNi by melting of prealloyed powders followed by natural cooling. The use of prealloyed powders guaranteed atomic-level mixing. In accordance with the literature, the resulting ingot had a face-centered cubic structure. A typical dendritic-interdendritic microstructure was obtained which was explained by partitioning during solidification and grain boundary wetting phenomenon. Post-annealing treatment improved chemical homogeneity without crystallographic phase change. This work shows the feasibility of melt-aided synthesis of CoCrFeNi HEA under static conditions using a conventional laboratory furnace.