| For many years the thermal aspects of cutting have been studied, since cutting temperatures strongly influence tool life, finished product and cutting forces. It is important to understand the factors that influence the heat generation, the heat flow and the temperature distribution in the tool and work material near the cutting tool's edge. However, the experimental determination of the amount of heat and the heat distribution in this crucial area is technically difficult, and the progress on this fundamental problem has been slow.; High speed machining, recently applied in the aerospace industry for the cutting of light alloys, i.e. aluminum, has been adopted by other industries due to its many advantages. In addition to significantly reducing production time, it is thought that high speed machining decreases the time for conduction of generated heat into the workpiece, resulting in less thermal distortion of the finished product. Cutting forces are decreased at higher speeds and less residual stress is observed. However, it is often assumed that the temperatures generated during high speed machining are much more higher than those in machining at conventional speeds and that there are thermal restraints on cutting velocity during high speed machining, i.e. temperatures generated at and near the cutting edge of the tool determine the maximum possible metal removal rate.; In this investigation, the Hopkinson bar is preferred to traditional machining methods because it can perform high speed orthogonal cutting in a single shot thereby eliminating the need to overcome machine vibration, while performing high resolution temperature measurements over the requisite small areas. High speed infrared detectors are the technique selected to measure the temperature distribution.; The experimental technique developed is described in detail. A parametric study employing 6061-T6 aluminum alloy as the workpiece material is performed and the results discussed. The heat generated in the primary shear zone and in the tool/chip interface is visualized. The effects of depth of cut, rake angle and cutting speed on the temperature field of the workpiece close to the cutting tool edge are evaluated. In addition, 1018 steel was tested at high cutting speed for several rake angles. |
