Abstract
Cutting temperature distribution along the curved cutting-edge of small ball endmill is measured with an three-color infrared radiation pyrometer using an optical fiber. The high speed air spindle unit is adopted to the ordinary milling machine so that the maximum spindle revolution of 40000rpm is attainable. The ball radius of the carbide cutter is 3mm and the side cutting of carbon steel at spherical ball is executed without cutting fluid. The influence of spindle rotational speed, radial depth of cut and feed per tooth on temperature distribution at the flank face are examined. The maximum temperature about 700℃ is obtained at the peripheral cutting edge and it decreases along the ball cutting-edge toward the ball tip. The relatively large temperature difference arises along the ball cutting-edge at higher spindle revolution because the cutting speed depends on the local tool radius. The depth of cut and feed per tooth, on the other hand, affect the overall temperature at the ball cutting edges.
