Harvesting superior intrinsic plasticity in nitride ceramics with negative stacking fault energy

Abstract

Ceramics face an everlasting challenge from their intrinsic brittleness at room temperature, which can lead to early-stage catastrophic failures. The fatal disadvantage primarily results from the high critical-resolved shear stress required to initiate dislocation movement and the limited number of operational slip systems. Here, we propose a new strategy for designing deformable ceramics by negative stacking fault energy (SFE), which realizes energetic barrier reduction of dislocation motion and slip system expansion. This way, we harvested a superior room-temperature compressive plasticity in TiN/TaN superlattice by successive and extensive atomic plane faulting and twinning. This strategy sheds light on the design of intrinsically ductile ceramics.