Research Highlights
High-throughput Fabrication and Characterization on Engineering Materials team found "supercritical elasticity phenomenon", and successfully prepared nicofega single crystal fiber with zero lag and ultra-high elastic strain in wide temperature range, with fiber diameter of 30-500 microns and length of more than 1 meter. At room temperature, the alloy fiber has an elastic deformation of up to 15.2% with zero hysteresis, and the maximum hyperelastic stress is up to 1.5 GPa. In the temperature range of 123-423k, its hyperelastic energy basically does not change with the temperature. In addition, the material has excellent cycle stability and large elastic energy storage (~ 80 mjm-3) under high strain (10%), and has a wide application prospect in aerospace and intelligent manufacturing. The results were published in the international top journal Nature Materials in March 2020 (nature materials, 2020, DOI: 10.1038/s41563-020 - 0645-4, if = 38.887).
In this study, advanced characterization methods such as high-energy X-ray diffraction, neutron scattering and high-resolution scanning transmission electron microscopy have been used to reveal that this kind of ultra-high elasticity with zero delay in wide temperature range is "supercritical elasticity". The discovery of "supercritical elasticity" in alloys overturns the classical theory of martensitic transformation, which restricts the metal materials to obtain hysteresis free and super high elasticity. It not only broadens the research field of elastic strain engineering, but also opens up a new research and application direction for super high elastic functional materials. Through the control of the ordered and disordered atomic scale entangled structure states in crystal materials, it is expected to obtain other singular physical properties, and provide innovative research ideas and methods for the unsolved mysteries related to supercritical phenomena and phase transition behavior in solid physics.