A polishing method for single crystal diamond (100) plane based on nano silica and nano nickel powder

Single crystal diamond is widely used in the manufacturing of diamond cutting tools. In this work, the diamond (100) plane which is always orientated as the rake face of diamond cutting tools is polished by using a polishing pad covered with nano silica and nickel powder. The results show that the polishing with nano nickel powder can achieved the satisfactory surface quality in a defined polishing time of 140 min, in which the surface roughness of the polished diamond (100) plane reaches to 0.25 nm Ra and 2.30 nm PV in a scanning area of 50 × 50 μm2. Raman spectra analysis further reveals that graphitization or amorphization occurs on the diamond surface during polishing with nickel powder. Finally, based on the polishing method with nano nickel powder, the influence of the polishing parameters on the achieved surface quality is investigated so as to optimize the polishing parameters. 3D surface topography of the diamond (100) plane polished by the polyurethane pad coated with nano nickel (scanning area: 50 × 50 μm2). [Display omitted] •A polishing method by using nano silica and nano nickel powders is established.•Surface roughness of the polished diamond (100) plane reaches to 0.25 nm Ra.•Grinding induced micro grooves on diamond surface are effectively removed.•This polishing method can be employed as a passivation solution for diamond tool.