| 摘要 |
PROBLEM TO BE SOLVED: To provide a cutting tool made of surface covered cemented carbide a hard covering layer of which displays excellent abrasion resistance in high speed cutting work of heat resisting alloy. SOLUTION: This cutting tool made of surface covered cemented carbide is made forming the hard covering layer, on the surface of a carbide substrate by vapor deposition, which is constituted of (a) an upper layer and a lower layer both of which are made of (Cr, Al, B)N, the upper layer which has average layer thickness of 0.5 to 1.5μm and the lower layer which has average layer thickness of 2 to 6μm respectively, (b) the upper layer which has an alternately laminated structure of a thin layer A and a thin layer B single layer average layer thickness of both of which is respectively 5 to 20n (nanometer), the thin layer A and B which are constituted of a (Cr, Al, B)N layer to satisfy a specific composition formula, and (c) the lower layer which has a single phase structure and is made of the (Cr, Al, B)N layer to satisfy a composition formula: [<SB>Cr1-(X+Y)</SB>Al<SB>X</SB>B<SB>Y</SB>]N (but X shows 0.50 to 0.70 and Y shows 0.005 to 0.05 in an atomic ratio). COPYRIGHT: (C)2006,JPO&NCIPI
|
