Study On The Mechanism Of The Coloured Oxidtion Film On The Surface Of The Stainless Steel By Laser

With the development of science & technique and the improvement of people's standard of living, the demands to stainless steel produce are increasing. The stainless steel produce applied to the decoration of the supermarket, the bank, the station, the showplace, and the industrial arts of exhibition design, establishment of elevators, appliance wiring, automobile industry ,electronic industry, marking and scutcheon are welcome. According to the market research, the stainless steel produces are high margin, and are in heavily demand.The technique to obtain coloring stainless steel produce such as: printing, erosion, emulsion coating and oxidation。Comparing with those techniques, the laser technique is to obtain oxidation film in localing area.Our team achieved colorful pattern successfully on the surface of the stainless steel by using Nd:YAG laser. If we want to obtain uniformity oxidation film ,because of the thermal effect, the temperature have effect on the oxidation film, we studied using a complex filter for temperature uniform in laser distribution dregion . We use an amplitude filter, a phase filter and Fourier lenses to transform a Gaussian beam to be a flatting beam. Basing on the paper[27] ,we stimulated that model by using numerical value ,and the results showed that our theory results agree with the experimental results.In the liquid phase medium, the temperature has heavy effect on the growing velocity of oxidation film. Because the acid solution do not absorb the 1.06μm laser beam, when using this laser beam to heat up local area on the surface of the stainless steel sheet, the energy of the beam is absorbed by the stainless steel sheet, these energy activated the mental ion, so the surface of stainless steel was eroded ,no oxidation film grow on it.In gas phase medium, we achieve colored oxidation film on the surface of the stainless steel steel. When the energy of the laser beam is low, the oxidation film is yellow ,and when the energy is higher, the film looks blue. We also studied the relationship between some factors ,such as the laser power, the pulse width and the coloration of the oxidation film. We do not think about some factors ,such as the surface smoothness and the Surface roughness, have some effect on absorbing to the 1.06μm laser beam.