Self-healing of fractured diamond

Materials that possess the ability to self-heal cracks at room temperature, akin to living organisms, are highly sought after. However, achieving crack self-healing in inorganic materials, particularly with covalent bonds, presents a great challenge and often necessitates high temperatures and considerable atomic diffusion. Here we conducted a quantitative evaluation of the room-temperature self-healing behaviour of a fractured nanotwinned diamond composite, revealing that the self-healing properties of the composite stem from both the formation of nanoscale diamond osteoblasts comprising sp2- and sp3-hybridized carbon atoms at the fractured surfaces, and the atomic interaction transition from repulsion to attraction when the two fractured surfaces come into close proximity. The self-healing process resulted in a remarkable recovery of approximately 34% in tensile strength for the nanotwinned diamond composite. This discovery sheds light on the self-healing capability of nanostructured diamond, offering valuable insights for future research endeavours aimed at enhancing the toughness and durability of brittle ceramic materials. The room-temperature self-healing behaviour of a nanotwinned diamond composite is quantitatively evaluated and found to stem from both the formation of nanoscale diamond osteoblasts and the atomic interaction transition from repulsion to attraction.

Automated summary

The room-temperature self-healing behavior of a nanotwinned diamond composite is quantitatively evaluated and found to stem from both the formation of nanoscale diamond osteoblasts and the atomic interaction transition from repulsion to attraction.