Milling tool's flank wear prediction by temperature dependent wear mechanism determination when machining Inconel 182 overlays

Inconel 182 overlays is popular for its advantageous mechanical and chemical properties at elevated temperature, which is widely used as anti-corrosion material deposited on cast seal surface of nuclear steam turbine. The Inconel overlays deposited on the complicated shape of cast seal requires further milling process to obtained high quality surface. However, Inconel 182 overlays is a typical difficult to cut material due to its low thermal conductivity, plastic deformation and severe adhesion, which result in catastrophically tool wear. Therefore, it is necessary to establish a milling tool wear model to predict actual tool wear so as to save tool costs. Unfortunately, the existing tool wear models are all established to predict tool wear in continuous turning process, not suitable for the interrupted milling process. To solve this problem, this paper firstly determines the threshold temperature of adhesive wear, diffusive wear and oxidative wear of the cemented carbide and its basic TiAlN or TiN coating against Inconel 182 overlays by sliding wear tests, which is the emergence criterion of different tool wear mechanism. Based on the above wear mechanism determination, a mathematical model of milling tool's flank wear is then proposed by acquisition of the real time cutting force and temperature. The results show that the errors of the predicted minimum values are all within 10%, demonstrating that this model can be used to predict the milling tool's flank wear when machining Inconel 182 overlays.