Borrowed dislocations for ductility in ceramics.

The inherent brittleness of ceramics, primarily due to restricted atomic motions from rigid ionic or covalent bonded structures, is a persistent challenge. This characteristic hinders dislocation nucleation in ceramics, thereby impeding the enhancement of plasticity through a dislocation-engineering strategy commonly used in metals. Finding a strategy that continuously generates dislocations within ceramics may enhance plasticity. Here, we propose a "borrowing-dislocations" strategy that uses a tailored interfacial structure with well-ordered bonds. Such an approach enables ceramics to have greatly improved tensile ductility by mobilizing a considerable number of dislocations in ceramic borrowed from metal through the interface, thereby overcoming the challenge associated with direct dislocation nucleation within ceramics. This strategy provides a way to enhance tensile ductility in ceramics.