A STUDY ON ULTRASONIC ELLIPTICAL VIBRATION CUTTING OF HARDENED STEEL USING PCD TOOLS

Ultraprecision machining of hardened steel by the conventional cutting (CC) technique using diamond tools is impossible because of highly chemical affinity between carbon and iron at higher temperature during machining. An intermittently cutting technique, namely, ultrasonic elliptical vibration cutting (UEVC) technique has been being applied for high-quality machining of various difficult-to-cut materials for the last decade. However, study on machining of hardened stainless steel using polycrystalline diamond (PCD) tools applying this cutting technique has not been reported yet. This study presents an experimental study on UEVC of hardened stainless steel (a typical Stavax of 49 HRC) using PCD tools. Face cutting experiments have been carried out to investigate the effects of conventional machining parameters: depth of cut, feed rate, and spindle rotational speed on the performance parameters such as cutting force, tool flank wear, surface roughness and chip formation. A minimum surface roughness R value of 10 nm, measured by a stylus profilometer, was achieved. It can be concluded that, while applying UEVC technique, the inexpensive PCD tools compared to the single crystal diamond tools can be effectively applied to obtain optical surface for producing precise dies and molds from hardened steel.