УНИКАЛЬНАЯ АТОМНАЯ СТРУКТУРА МЕТАЛЛОВ В МОМЕНТ РАЗРУШЕНИЯ ЛАЗЕРНЫМ УДАРОМ

To effectively control the mechanical properties of structural materials and design their safety margins, understanding the properties of metal fracture is essential. However, it is difficult to experimentally investigate the atomic structures at the moment of fracture. This study aims to investigate the atomic structure changes during the fracture process of copper, which is essential for controlling the mechanical properties of structural materials and designing their safety margins. The authors used X-ray absorption spectroscopy and X-ray diffraction to in situ examine the atomic structure changes on the nanosecond scale during the fracture process triggered by an optical laser. The results showed that there was an irreversible change in the deformation state on the nanosecond scale, with the initial elastic deformation state superseded by a plastic deformation state and ultimately transformed into a "short-range-disorder-only" state at the moment of fracture. This unique “short-range-disorder-only” state, which has never been reported using conventional ex situ analytical techniques, triggered metal fracture; therefore, controlling the occurrence of this state could suppress fracture and allow the design of reasonable metal safety margins to avoid overengineering.