Stacking Fault Energy Engineering as the Pathway to Materials With Exceptional Performance.

Abstract

Stacking fault energy (SFE) is a core thermodynamic parameter governing defect evolution, offering a critical pathway to circumvent the strength-ductility trade-off in advanced materials. However, its precise prediction faces a profound physical discrepancy: the ideal intrinsic SFE (γ_isf) predicted by first-principles calculations often deviates significantly from experimentally measured apparent SFE (γ_app), which is intensely modulated by microstructural constraints and local chemistry. Furthermore, SFE tailoring paradigms differ fundamentally across material systems. In complex metallic solid solutions, such as high and medium entropy alloys, SFE engineering relies predominantly on macroscopic alloying and reshaping the dynamic generalized stacking fault energy (GSFE) landscape via chemical ordering. Conversely, in non-metallic materials like structural oxides and advanced ceramics, compositional tuning is generally insufficient. Overcoming their intrinsic brittleness requires transforming the SFE into a defect-conditioned dynamic energy landscape, manipulating planar fault nucleation and thermodynamic stability via defect chemistry, interfacial templating, and non-equilibrium processing. This review summarizes the fundamental physical frameworks of SFE engineering, comparing cutting-edge tailoring strategies and their mechanical impacts across metallic and non-metallic systems to guide the design of next-generation structural materials.