RAINBOW COLOR DEVELOPMENT PROCESSING METHOD

摘要

PURPOSE:To provide the rainbow color development processing method which subjects a metallic surface to ornamentation processing to variously change the tints of reflection gloss by directions of incident light and viewing angles like rainbow colors. CONSTITUTION:The surface of a work piece W consisting of a metallic material is irradiated with the convergent pulse laser beam L in reactive gas in such a manner that pulses are cast many times to the same position. As a result, the thin film P consisting of the reaction product of the metallic components of the work piece W and gaseous components is formed on the surface of the work piece W in the fore stage of this irradiation and the laser beam La propagating in the plane direction with the thin film P as a waveguide and the laser beam L for irradiation are interfered in the post stage of the irradiation, by which the fine ruggedness G corresponding to the intensity distribution of the interference fringes is formed on the surface of the work piece W.