Metastable Nanoprecipitates in Alloys: Phenomenology and Atomistic Simulation

Metastable disperse states arising from decomposition in alloys are of considerable interest and have an important practice-related significance, providing high strength properties. Recently, the stabilization mechanism of disperse states through the formation of a shell enriched in alloying elements has attracted special attention. The paper presents a concise overview of the theoretical concepts pertaining to the formation and stabilization of disperse states in alloys, along with recent findings from first-principles atomistic simulations of Al–Cu–X, Fe–Cu–X, and Al–Sc–Zr alloys, wherein precipitates with a core–shell structure have been observed. Furthermore, the paper addresses the conditions of kinetic and thermodynamic stabilization of precipitates in relation to coalescence processes during annealing.