PRECISION MACHINING OF DIAMOND BY UTILIZATION OF GRAPHITIZATION PHENOMENON DURING CUTTING PROCESS

摘要

Diamond is the hardest material; therefore, it is used as tools for ultra-precision machining. Recently, it is expected to apply diamond for molds of ultrasonic machining. However, when a diamond is used as a product, it must be shaped into the arbitrary shape, In order to get a bulk pattern of diamond, usually polishing a diamond by diamond-powder is done extensively, but this method is costly and takes long processing time. This research is an investigation of precision machining for a single crystal diamond by ferrous material using cutting process, in order to get the diamond into bulk and three-dimensional shapes. It is found that ferrous material can remove and shape diamond, even though diamond is much more harder than ferrous material. The external surface of ferrous material is transferred to the diamond surface during the cutting process. This machining method is achieved by utilization of diamond graphitization and tool wear during the cutting process. The removal rate has been measured experimentally, and the removal rate is calculated on based graphitization. The calculated value of removal rate matches closely the experimental removal rate. The machining temperature is effective on machined depth, since the graphitizing process is affected by the temperature degree. Several shapes of diamond are produced by present machining method, such as a truncated pyramid, lattice grooves shape and several surfaces shape of diamond, where the machining time for each sample is less than one minute.