C-C bond rupture initiated graphitization achieves highly efficient diamond polishing

N Liu and L Lei and H Lu and HL Jiang and YJ Zhang and JF Xiao and JG Zhang and X Chen and JF Xu, INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, 287, 109958 (2025).

DOI: 10.1016/j.ijmecsci.2025.109958

Diamond is the ultimate semiconductor for power devices that operate at high-power, high-temperature, and high-frequency conditions. However, diamond polishing is challenging owing to its extreme hardness and brittleness. In this study, a novel material removal mechanism of C-C bond rupture initiated graphitization for highly efficient diamond polishing was proposed. Linear reciprocating sliding experiments demonstrated that the diamond material was removed in the form of graphite rather than chipped off as diamond fragments, and a high wear rate was achieved under low gas pressure and ultraviolet (UV) irradiation conditions. Based on this, a novel low-gas-pressure UV- assisted polishing method was proposed as a highly efficient approach for polishing diamond. A high material removal rate of 15.8 mu m/h was achieved, and the high efficiency was verified by the rapid surface roughness improvement from 465.5 to 3.7 nm within 70 min. Subsequently, a ReaxFF molecular dynamics simulation was conducted to clarify the atomic removal mechanism. Atomic attrition was accompanied by the rupture of C-C bonds, and the reconstruction of diamond into graphite was activated by large amounts of C-C bond ruptures. We propose that the reconstruction of diamond into graphite activated by a large number of C-C bond ruptures is essential for achieving a high material removal rate.

Return to Publications page