PREPARATION OF CUTTING TOOL

摘要

PROBLEM TO BE SOLVED: To lessen the need for polishing work by forming the cutting edges of a cutting tool by emission of a laser cutting beam through a superhard polishing material layer. SOLUTION: A CVD diamond layer 10 is cut by using a laser beam 16 and is divided to two pieces 12 and 14. The laser beam 16 is so emitted as to cross the CVD diamond layer 10 from one flank 18 to another flank 20 toward an arrow, by which the cutting is executed. The laser beam 16 is directed at an angle exclusive of 90 deg. with the front surface 22 of the CVD diamond layer 10. The pieces 12 and 14 have the edges 24 and 26 formed by the incidence of the laser beam 16, i.e., the cutting toward the inside of the CVD diamond layer 10. The edges 28 and 30 on the exit side are sharper than the edges 24 and 26 on the incident side and have decreased defects. The angle α is typically 20 to 40 deg..