Monitoring the wear of turning tools with the electromechanical impedance technique

In this study, Inconel 718 and Ti6Al4V alloys were machined using ceramic (WG 300), and carbide (G20M Grade) inserts, respectively. The focused application was grooving. The tool wear was observed with traditional methods and with a new approach, the electromechanical impedance (EMI) technique. First, different machining durations were determined to obtain a different level of worn tools, and the wear amounts of tools were measured using a specialized optical microscope. Then, the electromechanical impedance signature of the new and worn tools was measured with two different piezoelectric sensors. It was understood that the wear level of the tools could also be determined with the EMI method. In order to evaluate the damage quantitatively, RMSD and CCD Damage Indexes (DI) were used. With this proposed method, it was thought that the tool wear level and the remaining machining time from the tool could be predicted with calculated DI. Additionally, a second study was conducted on irregularly worn carbide tools; it was understood that sensors location has a significant role in determining the wear zone; for the current setup, the flank wear could be detected more effectively with the EMI method than the wear on the rake side of the cutting tool.