Study on Cutting Force and Tool Wear in Machining of Die Materials with Textured PCD Tools Under Ultrasonic Elliptical Vibration

Machining of steel-based alloy (STAVAX) and tungsten carbide (WC) is very challenging due to their superior hardness. Severe wear in the machining of the die materials is the dominant problem. Texturing on the rake face of the tool and ultrasonic elliptical vibration cutting (UEVC) may resolve this issue and could prolong tool life. The patterns on the rake face of the tool entrap the chip and debris created in machining and prevent abrasion. During UEVC the flank face of the tool does not contact the workpiece and the rake face of the tool helps the chip evacuate from the machining area when the tool disengages with the workpiece. Thus, UEVC reduces cutting force and tool wear compared to conventional cutting. This paper investigates the cutting performance and tool wear in machining of the die materials with textured polycrystalline diamond (PCD) tools under UEVC. The linear patterns parallel or perpendicular to the chip flow are engraved on the rake face of the PCD tools with the focus ion beam (FIB) process. Orthogonal cutting experiments are carried out on ultra-precision machine tools with and without UEVC. Machining under UEVC remarkably reduces the cutting and thrust force and improves tool life. For machining of STAVAX with the textured PCD tool, the linear patterns alone do not improve the cutting, but they improve the cutting when they are combined with UEVC. In machining of WC, the linear pattern becomes effective by slightly decreasing the thrust force and friction coefficient when UEVC is not applied.