Study on machinability of silicon irradiated by swift ions

Diamond cutting of hard and brittle materials is difficult owing to poor surface quality and severe tool wear. It has been clear that ion implantation can be used to improve the machinability. In previous studies, surface modification is realized by the nuclear collision cascade that induces phase transition during the implantation. Except for the nuclear collision process, electronic interaction between the incident particles and the target material, such as ionization, also occurs particularly during a high-energy ion implantation. However, the influence of ionization on the machinability has not been studied. In this paper, modification on the nanocutting of silicon by MeV oxygen ions is studied. Molecular dynamics simulation is conducted to reveal the nanocutting process on silicon with irradiation damages. Experiments show an enhancement in the critical undeformed chip thickness that is crucial in machining of brittle materials.