Micro end mill tool temperature measurement and prediction

The objective of this work is to characterize the heat transfer in micro end mill tools during machining operations. This analysis will aid in the design of heat dissipation strategies that could potentially increase tool life and machining precision. Tool temperatures, above the unmachined workpiece surface, have been measured using an infrared camera during slot milling of aluminum (6061-T6) and steel (1018) with 300 μm-diameter two-flute tungsten carbide end mills. The measured temperatures compare favorably with temperature distributions predicted by a two-dimensional, transient, heat transfer model of the tool. The heat input is estimated by applying Loewen and Shaw’s heat partitioning analysis. Analysis of heat transfer in the tool found that 46 s into a cut conduction through the length of the tool, storage in the tool, and convection from the surface account for 41.5%, 45%, and 13.5% of the heat generated during machining. Thermal expansion and cooling strategies are discussed.