SURFACE-CLAD CUTTING TOOL

摘要

PROBLEM TO BE SOLVED: To provide a surface-clad cutting tool excellent in pitching resistance and wear resistance.SOLUTION: A surface-clad cutting tool is obtained by depositing/forming a hard clad layer on the surface of a tungsten carbide-based sintered hard alloy substrate. The surface-clad cutting tool is characterized in that (a) the hard clad layer is a multiple nitride layer containing Al and Cr and a ratio of the content of Cr to the total amount of Al and Cr is 0.2-0.5 (atomic ratio) and (b) the hard clad layer 20, which is deposited/formed on a region 17 extending from a cutting edge 16 on the relief face 21A of a tool substrate 14 to a position parted by 100 μm from the cutting edge of the relief face to the opposite side, has a granular crystal structure, the average particle size of crystal grains on the surface 19 of the hard clad layer formed on the region is 0.2-0.5 μm, the average particle size of crystal grains on the interface 18 between the tool substrate 14 and the hard clad layer 18 is smaller than the average particle size of crystal grains on the surface 19 of the hard clad layer by 0.02-0.1 μm and a diameter/length ratio of the crystal grains each having ≤0.15 μm particle diameter is ≤20%.