Quantum chemical calculations of thermodynamic and mechanical properties of the intermetallic phases in copper–scandium alloy

Abstract

To understand how the intermetallic phases of Cu–Sc influence the thermal stability and mechanical strength of Cu–Sc alloys, thermodynamic and mechanical characters of the Cu–Sc alloy have been calculated by first-principles. The lattice parameters of Cu4Sc phase are obtained by calculated and the CuSc phase is found to be the most stable phase based on formation energies. In the binary Cu–Sc alloy, the shear moduli of Cu4Sc and Cu2Sc phases along the [100](001) crystal orientation are easier than those along the [100](010) crystal orientation, respectively. Pure Cu phase acts as the most stiffness phase while [Formula: see text]Sc phase has the lowest stiffness. Cu4Sc phase possesses the best plasticity while CuSc phase possesses the worst plasticity. Cu4Sc phase is the most ductile phase while [Formula: see text]Sc phase is the most brittle phase. From the partial density of states, the valence bands of binary Cu–Sc phases are dominated by the Sc-[Formula: see text] states.