Tool Wear of PVD Coated Carbide Tool when Finish Turning Inconel 718 under High Speed Machining

This paper reports the results of an experimental works, where Inconel 718, a highly corrosive resistant, nickel-based super alloy, was finish-turning under high speed conditions. The machining processes were carried out at three different cutting conditions (DRY, MQL 50 ml/h and MQL 100 ml/h), three levels of cutting speed (Vc=90, 120 and 150 m/min), two levels of feed rate (f=0.10 and 0.15 mm/rev) and two levels of cutting depth (d=0.30 and 0.50 mm). The tool wear and flank wear progression were monitored, measured and recorded progressively at various time intervals. The experiments indicated that MQL condition performs better than dry condition in term of tool life. Most of the tool failures during machining were due to gradual failure where abrasive and notching wear on the flank face was the dominant followed by, fracture on the flank edge and nose radius. Tool failure due to crater wear was not significant. Wear mechanism such as abrasive and adhesion were observed on the flank face and diffusion wear was observed on the rake face.