Study On The Surface Coloration Mechanism Of Stainless Steel Induced By Nanosecond Laser

Laser-induced surface coloration technology has attracted great attention from researchers and the market due to its advantages of simple procedure,high precision,easy automation and environmental protection.However,the stability of coloring and the interoperability of process parameters restrict its application in industry.Therefore,in this paper,532 nm nanosecond laser was used to color the stainless steel surface to study the coloring mechanism of the sample surface and the relationship between the process parameters and the surface coloring effect,so as to provide certain help for the similar laser in the study of metal surface coloring and promote the application of this technology in industry.According to the materials and equipment used in the experiment,the experiment design was carried out,and then the color was prepared on the sample surface according to the single variable and matrix test method.Finally,the surface morphology,elements,phase,film thickness and reflectivity of the colored sample were measured and analyzed with the help of the detection instrument.The research results and conclusions of this paper mainly include the following:(1)Black,brown,green,cyan,blue,purple and other colors were successfully prepared on the surface of stainless steel,and their processing parameters were determined.The test results of the colored samples showed that the surface of the samples irradiated by the laser had oxidation reaction and generated corresponding oxides.The selected process parameters were different,and the morphologies generated on the surface of the samples were also different,which were mainly divided into two structures,namely the periodic accumulation morphologies and the oxidized films.(2)The study on the surface coloring mechanism of stainless steel shows that the surface color of the sample is not only related to the interference effect of the film,but also affected by the microstructure of the sample surface.(3)The influence of laser process parameters on the surface coloring effect of the sample is realized by the laser energy density loaded onto the sample surface.The results of temperature field simulation show that the temperature generated by pulse action in the center region of different color samples is different due to the different process parameters,which affects the oxidation reaction on the sample surface.(4)CIEL*a*b*color space was selected to analyze the color difference between the colored samples,the repeatability and stability of laser-induced surface coloring of stainless steel were studied,and the adjustable range of process parameters for the preparation of each color sample was given under the condition of satisfying the stability.