Synthesis of alumina ceramic meta-fibers with tensile super-plasticity

Ceramics are prized for exceptional strength, but their inherent brittleness has long been a fundamental bottleneck. Here, we report tensile plastic Al₂O₃ meta-fibers that achieve a combination of high tensile strength (1.94 GPa) and large plastic strain (10.01%), with micro-strain reaching 194%. This is enabled via a phase-regulation strategy that constructs high-purity unsaturated [AlO₅] coordination with disordered oxygen lattices in Al₂O₃ fibers. The metastable [AlO₅] fundamentally alters the deformation mechanics by reducing the energy barrier for bond breaking and reformation, while the disordered oxygen lattice facilitates extensive atomic displacement, collectively enabling intrinsic plastic behavior. This local plasticity accumulates in high-purity networks, ultimately achieving macroscopic tensile plasticity of fibers, challenging conventional understanding of ceramic deformation. These plastic fibers can be twisted and woven into high-strength, stretchable refractory ceramic fabrics. Our work establishes metastable phase customization as a universal paradigm, opening a promising pathway for designing superplastic ceramics.