Product Code: ICAL07_M1005

Multi-Oxides Thin Film Formation on Iron-Base Metal by YVO4 Pulsed Laser Color Marking
Authors:
Hiroyuki Niino, Natl Inst Adv Ind Sci & Technol (AIST); Tsukuba Japan
Seisuke Kano, Natl Inst Adv Ind Sci & Technol (AIST); Tsukuba Japan
Tadatake Sato, Natl Inst Adv Ind Sci & Technol (AIST); Tsukuba Japan
Kaoru Itagaki, Itagaki Metals Co. Ltd; Sanjo Japan
Tomoyuki Togashi, Itagaki Metals Co. Ltd; Sanjo Japan
Hirofumi Shimura, Natl Inst Adv Ind Sci & Technol (AIST); Tsukuba Japan
Presented at ICALEO 2007

Laser marking is a useful technique to draw characters and patterns on metals as a monochromic color. Recently some researches reported coloring pattern drawing on the metal surface by infrared wavelength pulsed laser irradiation. They usually assumed the coloring mechanism by means of optical interference between the oxidation layer and base metal. On the contract, we produced multi-oxidized thin films which were fabricated by laser irradiation of YVO4 pulsed-laser at 30 kHz in the atmospheric condition on the stainless steel surface. The surface was marked as several monochromatic layers including purple, violet, ultramarine, orange, and green. The mechanism of coloring for this technique was assumed by oxidation metal color by FeOx, CrOx, NiOx, and Cr-Ni-O systems. The result of XRD analysis for the colored areas showed several types of oxides consisting FeO, Fe3O4, CrO, Cr2O3, Cr3O4, NiO, Ni2O3, NiCr2O4 and their mixed oxides which consisted oxygen vacancy structures. These oxides have their original colors for each composition and structure. If the mono-phase area producing it shows clear mono-color corresponding to the composition and structure, and appearing optical or electrical function due to oxygen vacancy. The interfaces of the multi-oxides thin films were discussed by XPS, FTIR, and Raman spectrometer.