Laser processing for reducing core loss of grain oriented silicon steel

A nonconstact technique for reducing the core loss of a grain oriented silicon steel has been developed by the use of Q-switched laser irradiation. Vaporization of the surface layer of the silicon steel by the laser irradiation induced a stress which resulted in a refinement of 180° domain wall spacing. This phenomenon reduced the core loss of the steel. It was found that the laser irradiation was more effective in a specimen with a higher magnetic induction and the core loss reduced by more than 10% under the optimum condition of the laser irradiation. Since the laser processing is a noncontact technique, it is easily applicable to the production line of the silicon steel.