| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce chipping of a cutting edge and eliminate deformation of the cutting edge by making the concentration of binder material larger in an area close to the peripheral boundary of a substrate than an area away from the peripheral boundary of the substrate. SOLUTION: A substrate 18 has two areas, that is, a binder unenriched area 20 and an outer binder enriched area 22 close to the peripheral boundaries 24, 26 of the substrate 18. A hard heat-resistant coating with at least two layers which are a CVD layer 30 and a PVD layer is bonded to the peripheral boundaries 24, 26 of the substrate 18, and the coating has the last PVD layer preferably outside of the last CVD layer. When the PVD layer has residual compressive stress, the excellent service life of a cutting edge is provided in steel planing. The inner CVD layer 30 is preferably formed of heat-resistant nitride such as Ti, Zr or Hf-nitride.</p> |
