Laser processing of diamonds and sintered c-BN in liquid

Using Q-switched and pulsed YAG lasers, a study on the clean processing of single-crystal and sintered diamonds, and sintered c-BN in liquid was condu cted. Using the proposed system, which involves introducing a steady laser beam onto the surface of the specimen immersed in a liquid, it was determin ed that KOH solutions of 10% (for diamonds), and 30% (for sintered c-BN) ar e the best-suited liquids for minimizing the formation of a detrimental hea t-affected zone on the processed surfaces. Single-crystal diamond samples w ere grooved up to 50 mu m in depth from the lower surface. Sintered diamond and sintered c-BN (cubic boron nitride) samples were grooved from the uppe r surface, and the depth of the grooves was controlled by changing the numb er of beam scan repetitions. This technique was applied to the cutting inse rts of the materials concerned, that is, for the preparation of the chip-br eaker groove near the cutting edges, which was followed by cutting tests. T urning operations for pure aluminum using single-crystal diamond insert, al uminum alloy using sintered diamond insert, and hardened steel using sinter ed c-BN insert were conducted to prove the effects of the grooves on breaki ng hairlike or ribbonlike strips into small pieces.