CUTTING TOOL MADE OF SURFACE COVERED CEMENTED CARBIDE PROVIDING EXCELLENT RESISTANCE TO CHIPPING BY HARD COVERED LAYER IN HIGH SPEED INTERMITTENT HEAVY CUTTING MACHINING

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool made of surface covered cemented carbide in which a hard covered layer provides excellent resistance to chipping in high speed intermittent heavy cutting machining. SOLUTION: The hard covered layer in the cutting tool made of surface covered cemented carbide formed by physically depositing the hard covered layer made of a composite nitride layer of Ti and Si on a surface of a tungusten carbide group cemented carbide substrate or a titanium carbon nitride cermet substrate at a whole average layer thickness of 1 to 15μm has a component concentration distribution structure in which Si component maximum containing point (Ti component minimum containing point) and Si component non-containing point (TiN point) exist alternately and repeatedly at a predetermined interval along the direction of layer thickness and Si component content is continuously changed from the Si component maximum containing point to the Si component non-containing point and from the Si component non-containing point to the Si component maximum containing point. Furthermore, the Si component maximum containing point satisfies composition formula: (Ti1-XSiX)N (wherein, X denotes 0.20 to 0.50 by atomic ratio), and an interval between adjacent Si component maximum containing point and Si component non-containing point is 0.01 to 0.1μm in the hard covered layer. COPYRIGHT: (C)2003,JPO