Microcutting of Duralumin Using Focused-Ion-Beam-Processed Profile Cutting Diamond Bites

Single-crystal diamond bites can be used for ultrahigh-precision cutting of noniron metal materials because diamond has high hardness, stiffness and wear resistance. However, the diamond bite itself is processed using microdiamond particles, thus the shapes of the bite are limited to those using straight lines and simple circular arcs. In recent years, since the spot diameter of the iron beam of focused ion beam (FIB) devices has been reduced substantially, nanosize processing of various materials has become possible. In microcutting, it is possible to manufacture fine axes by sharpening blade edges and reducing cutting resistance. On the basis of this observation, we applied FIB to the finishing and shaping of the cutting edge of diamond bites. Using FIB-processed diamond bites, we manufactured a microshaft of 5 m diameter by lathe turning of duralumin. Furthermore, using a diamond tool whose edge had been sharpened by FIB, we succeeded in producing a highly accurate notch with 3 m depth in the microshaft.