An investigation of tool temperature in end milling considering the flank wear effect. (October 2017) - Cui, Di
Highlights: A new analytical model for predicting tool temperature in end milling considering flank wear is presented, which was rarely taken into account in previous temperature modeling in milling. The temperature model of tool in milling proposed in this paper is able to predict the temperature of fresh or worn tool accurately, though there is negligible difference between theoretical and measurement results. The heat partition on tool-chip interface gradually increases with the immersion angle of tool rise. At same cutting speed, it can be found that the partition increases with feed per tooth. However, when the cutting speed improves, it decreases at same feed per tooth. For heat partition on flank face, the flank wear has great effect on it. It is found that flank wear has great effect on tool temperature in milling of Ti6Al4V, but this influence does not become larger with the flank wear growth. The tool temperature begins to rise at high rate, then becomes steady state, i.e. temperature rise slowly, until reaches the peak value. Comparing the temperature peak value at all cutting parameters, tool temperature increases when the cutting speed or feed per tooth rises, and is more affected by feed per tooth. Abstract: In this paper, the tool temperature in end milling considering the flank wear effect was investigated by theoretical and experimental method. Theoretically, a new analytical model was developed to predict tool temperature in end milling. The new analytical model takes into account the flank wear effect, complex tool geometry and dynamic heat flux and partition in end milling. In order to tackle complex tool geometry, the tool is axially discretized into numerous tool differential elements. Based on heat source method, the heat transfer of each tool differential element is analyzed independently to model the temperature of each tool differential element. Then superpose the temperature of each tool differential element is to work out the total tool temperature. Experimental, according to single factor design, the end milling operations of Ti6Al4V were conducted with fresh and worn tool to determine the effect of flank wear on tool temperature and to validate the theoretical model. The experimental validation indicates that the new temperature model is able to predict the sharp and worn tool temperature in end milling accurately. The effect of flank wear on tool temperature, cutting force and heat partition on flank face is evident. At same flank wear, the tool temperature and cutting force primarily depend on feed per tooth and secondly on cutting speed. The heat partition on tool-chip interface increases with the increase of feed per tooth, but decreases when the cutting speed increases. There is an inverse trend in variation of heat partition on flank face compared with heat partition on tool-chip interface. Graphical abstract: