Comprehensive elemental screening of solid-solution copper alloys

Significantly improving the balance between the mechanical strength and electrical conductivity of solid-solution copper alloys is considered difficult. In this study, a comprehensive elemental screening framework is proposed to predict the solid-solution strengthening and electrical resistivity of copper alloys. Electrical resistivities are predicted by first-principles calculations, and a high degree of accuracy is obtained. Two models are considered to predict the solid-solution strengthening. One of them uses the generalized critical resolved shear stress formula and provides a reasonable accuracy for a testing set of our experimental data. The other model (using the first model as a feature with elemental features) has a high prediction performance for the testing set. Combining the predicted electrical resistivity and solid-solution strengthening, we establish a figure-of-merit formula for the comprehensive elemental screening. The formula provides reasonable results using the two models. The models predicted the known Cu–Ag (Cd, In, Mg) as high-performance copper alloys. All solute elements, H to Rn, including hypothetical copper alloys are ranked, and the less studied Cu–Au, –Hg, and –Tl are predicted to be high-performance structures. From economic, environmental, and healthcare perspectives, Cu–Mg is an appropriate choice according to the results.
For designing the balance between mechanical strength and electrical conductivity of solid-solution copper alloys, a figure-of-merit formula using theoretical formula, first-principles calculations, experimental data, and machine learning is established.