Analysis And Technology Research Of Color Marking Based On Composite Laser Induced Periodic Surface Structure Mechanism

With the development of industry and the improvement of living standards,color stainless steel products began to attract people’s attention.Compared with other metal coloring processes,laser induced surface periodic structure(LIPSS)has many advantages,such as low oxidation resistance,high temperature resistance,chemical corrosion resistance,bright color and so on.LIPSS is a kind of micro/nano grating structure formed by laser on the surface of materials.It is widely used in structural color,changing surface wettability and many "green technologies",and has a good development prospect.In this paper,the formation mechanism of LIPSS is firstly introduced.The formation principle of LIPSS is based on Sipe model and surface plasmon plasmon(SPPs),so as to form fringe structure which is very close to laser wavelength.This kind of fringe structure is similar to grating,and the grating diffraction will occur on LIPSS structure,forming color phenomenon.Secondly,the heating process of the interaction between the 532 nm laser and the stainless steel surface was simulated numerically.The relationship between the temperature rise of the stainless steel surface and the incident laser parameters was obtained,and the laser parameters near the melting threshold were determined.Then,the experimental platform was set up.Firstly,the periodical structure of the surface induced by a single laser beam was carried out,and the effects of different laser parameters on the LIPSS structure were analyzed.Then,the periodical structure of the surface induced by a composite laser beam(two laser beams with perpendicular polarization directions)was carried out.The fringe structure and surface appearance of LIPSS were observed under optical microscope and AFM.The values of LIPSS microstructure were measured and the best laser processing parameters were obtained.The LIPSS structure processed by composite laser beam has good color effect in most of the observation direction,which makes up for the problem that the color of LIPSS structure processed by single beam is too dependent on the observation direction,and improves the processing efficiency.