Mapping Time-Variant Modelling of Tool Wears and Cutting Parameters on Difficult-to-Machine Materials

The cutting parameters of CNC (Computer Numerical Control) machining are spindle speed, feed rate, depth of cut and width of cut. The selection of cutting parameters for difficult-to-machine materials is very important to improve machining efficiency and ensure machining quality. The tool wears is one of the most important representation for machining efficiency and machining quality. Therefore, the purpose of this paper is to develop the mapping time-variant model between tool wear and cutting parameters on difficult-to-machine materials. The time as a factor is added to design of experiment for the first time in order to considering time-variant. The experiment is been done on the machining centre with eight fixed set of cutting parameters which is arranged by the orthogonal design. The number of measurement of tool wears is 10 during the tool life cycle. The experiments data show well the processing the tool wear. Tool wear is approximated linear with time for a fixed cutting condition. Depth of cut is most significant factor to tool wear (life). Based on these collected data, the mapping time-variant model is developed using least square method. The proposed time-variant model will be used for the prediction of the dynamic tool life and reliability-based optimization of cutting parameters.