Method of preparing cutting tool substrate materials for deposition of a

Abstract

Methods for preparing a cutting tool substrate material for diamond coating include providing a grooved pattern on selected portions of at least the top surface and preferably also the sides of the substrate material. The pattern may be a cross-hatching, a diamond-hatching, or another design. The pattern is preferably applied to the tool substrate by scribing with a laser ablation tool. The pattern is designed to optimize adhesion of CVD diamond on the portions of the tool substrate which are expected to be most challenged during a cutting process. The dimensions of the pattern (e.g. the depth and spacing of scribe lines) are selected to provide the optimum combination of mechanical bonding and diamond nucleation during the CVD coating of the tool substrate. According to preferred aspects of the invention, the pattern is applied only to the portions of the surface not immediately adjacent to the cutting edge of the tool substrate, thereby sparing the geometry of the cutting edge itself. According to a one embodiment of the invention, the pattern includes a cross hatch on the top surface and on the side surfaces of the substrate. According to a another embodiment, the top surface is cross hatched in the center while the corners of the top surface are provided with parallel grooves. In another embodiment, the side surfaces are provided with parallel grooves parallel to the top surface.