Enhancing the performance of polycrystalline diamond tools for machining WC by ultrasonic elliptical vibration cutting method

Abstract

Precise machining or shaping of difficult-to-cut materials, such as tungsten carbide (WC), hardened steels, and optical glass, is always difficult to achieve by applying conventional cutting (CC) methods. Recently, the ultrasonic elliptical vibration cutting (UEVC) method has been successfully applied to machine some of such materials. However, this novel machining method has yet to be applied on WC using polycrystalline diamond (PCD) tools. This study aims to enhance the machining performance of commercial PCD tools for machining sintered WC by applying the UEVC method. First, the effects of cutting parameters on the cutting performance have been studied to establish a set of best cutting conditions. Then a case study has been carried out to justify whether the cutting performance in the UEVC method can further be improved by varying the related parameters but keeping the same machining rate. To substantiate the feasibility of UEVC method, a comparative performance of this method has been carried out with that of its CC counterpart. Experimental results have shown that the UEVC method results in better cutting performance with the decrease in the feed rate at the speed ratio of less than 1. A surface roughness of 0.027μm Ra has been achieved on a machining area about 1257mm2 with the UEVC method. The findings reveal that the performance of PCD tools could be enhanced by the UEVC method for ultraprecision machining of hard-to-cut materials.