Cu-Containing High Entropy Alloys for Nuclear Fusion Application

Abstract

Face-centered cubic Co-free Cu-containing solid solution concentrated alloys, Cu, CuNi, CuNiFe, Cu_0.3NiFeCr, Al_0.4CuFeCrNi₂ were prepared, and their microstructure, hardness, and tensile strengths were investigated in order to develop a new high entropy alloy with a high irradiation resistance, which is applicable for nuclear reactor components. All the as-cast alloys were identified as single-phase FCC alloys by X-ray diffraction analysis. While, the SEM observation indicated a new Cr-rich phase with Cu-rich phase in the annealed Cu_0.3NiFeCr alloy, which is probably due to low solubility of Cr and Cu in the alloy. After annealing at 1076°C for 120 hours, Cu_0.3NiFeCr alloy became a single-phase FCC. Mechanical property examinations indicated the highest Vickers hardness, the highest Tensile strength and the smallest elongation in the Al_0.4CuFeCrNi₂. The results indicate that the Al_0.4CuFeCrNi₂ alloy would have the potential to be a Co-free high-entropy alloy applicable to nuclear reactor components. In order to improve the elongation of Al_0.4CuFeCrNi₂, the detailed analysis of fracture surface and the optimization of annealing condition would be needed.

Fig. 1 XRD patterns for the Co-free Cu-containing solid solution concentrated alloys.