Domain refinement of grain oriented silicon steel by laser irradiation

The change of the domain structures and the magnitude of plastic deformation by laser irradiation were investigated. The amount of deformation estimated by the broadening of pseudo-Kossel lines in laser irradiated specimen is equivalent to, or greater than 10% strain in tensile deformation. New subdomains occur along laser irradiation spot lines. These subdomains may be attributed to compressive stress in the vicinity of laser spots. A change in the domain structures is observed as the number of laser irradiation spot lines increase. The 180° main domain wall spacing is not refined by single laser spot line. The 180° main domain wall spacing is, however, refined when the new laser spot lines on both sides of the first laser spot line are added. These phenomena were regarded as that caused by the tensile stresses between laser spot lines.