| 摘要 |
PURPOSE:To improve wearing resistance and tenacity in an end mill being classified by its functional part, by coating the surface of a tool main unit base material made of cemented carbides with a hard coating layer film forming its peripheral part in thickness larger than the thickness in the end cutting edge part. CONSTITUTION:The surface of a base material made of cemented carbides is coated with one or two or more layers of hard coating layer films by either carbide, nitride and oxide of metals in the periodic table 4a, 5a, 6a or Al, Si. A surface coating thickness is set to ratio in a relation where (peripheral edge part)/(end cutting edge part)=1.1 or more. While the surface coating thickness is desired to be 1.0-15mum in the point end part and 10mum or less in the end cutting edge part. In this way, a tool main unit enables its life to be extended while durability to be improved by increasing wearing resistance in the peripheral edge part, contributing to cutting a wall surface, while tenacity in the end cutting edge part relating to friction against a work. |
