Tool wear of ball-end mill with single straight cutting edge

The ball-end milling have become the most widely used machining process for sculptured surfaces. This report presents the tool life in milling steel (JIS-S45C) with ball-end mill which has single straight cutting edge. The life and the morphology of the tool wear under the condition that the cutting speed was 100(m/min) and the feed rate was 0.05(mm/tooth) were compared among three kinds of tool materials : cemented carbide (JIS-K10), micro grain carbide and titanium nitride cermet. The tool life became longer in this order : cemented carbide, micro grain carbide, titanium nitride cermet. The morphology of the tool wear of the titanium nitride cermet was adhesive, while those of the carbide tools were abrasive because the lower thermal diffusivity of the cermet makes the temperature of the cutting edge higher than the carbide tools.