Integration of high strength, flexibility, and room-temperature plasticity in ceramic nanofibers

The developing cutting-edge technologies involving extreme mechanical environments, such as high-frequency vibrations, mechanical shocks, or repeated twisting, require ceramic components to integrate high strength, large bending strain, and even plastic deformation, which is difficult in conventional ceramic materials. The emergence of ceramic nanofibers (CNFs) offers potential solutions; unfortunately, this desirable integration of mechanical properties in CNFs remains unrealized to date, due to challenges in precisely modulating microstructures, reducing cross-scale defects, and overcoming inherent contradictions between mechanical attributes (particularly, high strength and large deformation are often mutually exclusive). Here, we report a nucleation regulation strategy for crystalline/amorphous dual-phase CNFs, achieving an extraordinary integration of high strength, superior flexibility, and room-temperature plasticity. This advancement stems from the optimized dual-phase structure featuring reduced nanocrystal aggregation, increased internal interfaces, and the elimination of fiber defects, thus fully activating the synergistic advantages and multiple deformation mechanisms of dual-phase configurations. Using TiO₂, which is typically characterized by brittleness and low strength, as the proof-of-concept model, in-situ single-nanofiber mechanical tests demonstrate excellent flexibility, strength (~1.06 GPa), strain limit (~8.44%), and room-temperature plastic deformation. These findings would provide valuable insights into the mechanical design of ceramic materials, paving the way for CNFs in extreme applications and their widespread industrialization.