Self-healing on mismatched fractured composite surfaces of SiC with a diameter of 180 nm

Abstract

Self-healing on fractured surfaces of silicon carbide (SiC) is highly desirable, to avoid the catastrophic failure of high-performance devices working at extreme environments. Nevertheless, self-healing on a fractured surface of an amorphous and crystalline (AAC) composite structure of a brittle nanowire (NW) has not been demonstrated. In this study, self-healing is demonstrated on mismatched fractured surfaces of the AAC composite structure of a brittle solid for a SiC NW with a diameter of 187 nm. Fracture strength is 10.18 GPa for the AAC structure, recovering 11.7% after self-healing on its mismatched fractured surfaces. To the best of our knowledge, we firstly report the self-healing on mismatched fractured surfaces of the AAC structure for a brittle NW. This is a breakthrough of the previous prediction that self-healing could not be realized on a brittle NW with a diameter over 150 nm. A growth of 3 nm was found after self-healing on the gap induced by mismatched fractured surfaces, which is different from previous reports for pure amorphous and monocrystalline brittle NWs. To reduce the potential energy, coherent rebonding and debonding were performed to realize the atomic migration to fill the gap, resulting in the growth of gap of 3 nm to perform self-healing. Our findings shed light on the potential of self-healing for design and fabrication of next-generation high-performance SiC devices used in the vacuum and aerospace industries.