Formation energies, electronic properties and elemental diffusion of Cu–Cr–Nb (GRCop) alloys

Abstract

Electronic structure calculations with Hubbard U correction are completed to investigate the formation energies, electronic properties and elemental diffusion of Cu–Cr–Nb (GRCop) alloy. GRCop has a higher formation energy (−0.213 eV/atom) compared to Cu (0.031 eV/atom) due to the different atomic radii and locations of Cr and Nb atoms in the Cu matrix. The charge distribution associated with Cr and Nb is more likely to change during the synthesis of GRCop-42 due to the disparity in oxidation state as the composition changes. The temperature-dependent self-diffusion coefficient of Cu is analyzed above 473 K and found to be in the order of 10−10 cm2/s, which is comparable to the earlier reports. Self-diffusion of all the elements in GRCop is calculated to be significantly high, and this indicates that GRCop alloy is suitable for high-temperature applications including electronic packaging, welding electrodes, propulsion components, and heat-exchangers.