Evaluation of machinability under various cutting conditions in high-speed machining ball nose-end mills - effects of cutter orientation and cutting environments

摘要

High-speed machining generates concentrated thermal/frictional damage at the cutting edge and rapidly decreases the tool life. This paper is aimed at determining the effect of cutter orientation and the cutting environment on tool life, tool wear mechanisms when down milling. In this paper, the experiments were carried out in various tool paths and cutting environments, such as dry, wet and compressed chilled air, tool life were measured to evaluate machinability in high-speed milling of difficult-to-cut material and die steel. Tool life was measured in horizontal upwards, horizontal downwards, vertical upwards and vertical downwards. In addition, tool life was measured in dry, wet and compressed chilled air. For this study, a compressed chilled-air system was manufactured. The results show that a horizontal cutter orientation provided a longer tool life than a vertical cutter orientation. With respect to the cutting environment, compressed chilled air increased tool life. However, the wet condition decreased tool life due to the thermal shock caused by excessive cooling in high-speed milling and the compressed chilled air had little effect.