Modeling Static and Dynamic Cutting Forces and Vibrations for Inserted Ceramic Milling Tools

AbstractCutting tools with ceramic inserts are increasingly being used in machining of super alloys typically used in aerospace industry. The ceramic inserts make higher cutting speeds possible due to the higher temperature resistance compared to carbide inserts. However, the success of the process is very sensitive to the right selection of process parameters. In this study, analytical process models for indexable milling tools with round ceramic inserts are presented. These models can be used to determine the cutting parameters for optimum quality and maximum productivity. Firstly, geometry of the insert cutting edges under the effect of angles on the inserts was formulated. Then, an analytical cutting force model was developed. This allows analyzing the effects of the parameters on the cutting forces. A time-domain model was also developed to analyze the dynamic cutting forces and stability limits for the milling process. Afterwards, the models were implemented in a Matlab® GUI to make the applications of the models in the industry easy. Cutting force coefficients, which are needed to calculate cutting forces, were identified from cutting tests with Inconel 718 material. Then, the cutting force model was validated with cutting experiments. After obtaining modal data of the tool via tap testing, dynamic cutting forces and vibrations were simulated by means of the time domain model. A series of simulations was carried out to determine stability limits at certain operating conditions using the time domain model, and stability lobes for the tools under study were plotted