Tool Wear Characteristics of Small Diameter Ball End Mill on Ultra High Speed Milling at l00000min"' Rotation Speed

Experiments were conducted to investigate the tool wear of small diameter coated cemented carbide ball end mills using an ultra high speed milling machine with a maximum speed of 120000 min^-1 and feed speed of 100 m/min. The results showed that the tool life is suitable for actual use and indicated that the flank wear at the external circumference of the tool, where speed is maximum, determines the tool life. As the tool wear of this area conforms to Taylor's law, the cutting power required increases as wear progresses. Although the finished surface also deteriorates, the degree is slight. Experiments were also performed on wear reduction by changing conditions. The results showed that the feed rate and real cutting speed contribute considerably to wear, and serve as a criteria for selecting the optimum cutting conditions.