| 摘要 |
PURPOSE:To enable heat treatment having high utilizing efficiency of laser beam energy by shifting a working material in a conical mirror, making incident laser beam from bottom face side of the mirror and multiplicatively reflecting the laser beam at interval between the mirror inside face and the surface of the working material. CONSTITUTION:Center axis of the work 2 is aligned with center axis of the cone type mirror 1 having mirror surface in the inner face, hollow circular cone or polygonal cone shape and 2-15 deg. apex angle and penetrated and shifted at the prescribed velocity. The irradiation of the laser beam 3 is executed from opening part at the bottom face side of the cone type mirror 1. The beam flux forming the laser beam 3 is automatically converged while repeating multiple reflections at the interval between the inner face of the cone type mirror 1 and the surface of the working material 2. The reflectance at the inner face of the mirror 1 is high but the reflectance of the working material 2 (steel wire) is reduced in accordance with increase of the incident angle of the laser beam 3, and the laser beam is absorbed to the work 2 at the convergence part. By this method, the heat treatment can be continuously executed to the surface layer of the work 2 at few mum thickness. |
