Cut-off characteristic of CBN and diamond stick stones with pulsed YAG laser: laser cutting of superabrasive stone

In this Paper, laser cutting of super abrasive thin stick stone (SATSS) whose grains are CBN and diamond using Nd:YAG laser is studied. We have investigated cutting characteristics of SATSS and strength of the heat affected zone (HAZ) on the surface cut with laser. As a result, SATSS of 3 mm in thickness can be cut off with the width of 0.2 mm in maximum, and there is no chipping at the edge of the surface cut with laser. In the case of CBN stick stone, cutting time with laser is 2.5 times faster than that with diamond blade, and 15 times faster in the case of diamond one. There is a HAZ with a thickness of 0.05 mm. In this HAZ, the abrasive grains are oxidized and their crystal structures are changed by the heat of laser irradiation. However, laser is absorbed effectively by the HAZ, and the HAZ raises the strength of SATSS because the pores inside of the HAZ are closed by the re-solidified vitrified bond. From these results, it is shown that laser cutting can apply to the manufacturing of the SATSS and improve the productivity and the quality.