Papers by Keyword: Dynamic Friction Polishing Method

Abstract: The authors developed “Dynamic Friction Polishing (DF polishing) Method” utilizing a thermochemical reaction between a diamond workpiece and a metal. This method enables high efficiency abrasive-free polishing of single crystal and polycrystalline diamonds (PCD) by simply pressing them against a stainless steel (SUS304) disc rotating at a high peripheral speed (V_S>2500m/min). In the authors’ previous paper, a top of the diamond test piece (0.6mm×0.6mm, (100) plane) was removed at a rate of 2.6mm/min (0.94mm³/min) under the polishing condition of sliding speed V_S=4000m/min, loading pressure P=130MPa and polishing time t=10s. A bottleneck for practical use of this method is a high pressure over 100MPa required for pressing a diamond workpiece against a rotating stainless steel disc. In this paper, a high efficiency tool was manufactured by electro-spark deposition of highly reactive special metals on a base disc tool. Among various reactive metals Nb and W brought very high efficiency in the polishing of a single crystal diamond.

Abstract: This paper proposes a new dynamic friction polishing method which utilizes resistance heating for solving a problem of too high pressure on a workpiece in the previous dynamic friction polishing method proposed by the authors. In the new method, an electrically conductive diamond workpiece (which has proper electric resistance) is heated by an electrical current flowing from a stainless steel disc tool to the diamond workpiece during the dynamic friction polishing and the polishing efficiency increases remarkably even at a very low pressure on the workpiece. For example, polishing efficiencies of 233 and 800 µm/min are attained at low pressures of 2 and 5 MPa, respectively, at a disc sliding speed of 2500 m/min.