パルスNd:YAGレーザを用いたCBN及びダイヤモンド砥石の切断特性: 超砥粒砥石のレーザ切断

In this paper, the cutting characteristics of super abrasive stones using a pulsed Nd:YAG laser are studied. The influence of the heat on the stone surface cut by laser is investigated. As work materials, CBN stones and diamond stones with grain size of #2000 are used. As a result, the super abrasive stone of 3mm in thickness can be cut with the molten width of 0.2mm in maximum and with no chipping at the edge. The cutting speed of laser beam is 2.6 times faster than that of diamond blade in the case of CBN stone and 24 times faster in the case of diamond stone. There remains a heat affected zone (HAZ) in the stone surface and its thickness is about 0.02mm. In the HAZ, the abrasive grains are oxidized and their crystal structures are changed by the heat of laser irradiation. However, the HAZ raises the absorption of the laser beam at the stone surface and raises the strength of the stone a little because the pores in the HAZ are closed by the re-solidified vitrified bond. Therefore, laser cutting is useful for the manufacturing of the super abrasive stones in productivity and quality.超砥粒砥石の生産性向上を目標として, パルスNd : YAGレーザを用いた超砥粒砥石の切断に関する研究が行われている. 厚み3mmのCBN砥石およびダイヤモンド砥石を用いて切断実験した結果, ダイヤモンドブレードによる切断と比較して取り代および切断速度が改善され, 切断面の熱変質層には熱亀裂が存在せず, 良好な加工が可能なことを示した