Study On Laser Micro-Nanostructures Fabrication And Properties Of Stainless Steel Surface

Femtosecond laser micro-nano processing technology has aroused wide concern in recent years,the obtained micro-nanostructure surfaces have advantages of superhydrophobic,self-cleaning,colorful structural color,high efficiency light absorption.Those micro-nanostructure surfaces have showed a very high potential for applications in military camouflage,solar battery,aerospace,marine and other fields.The influence of energy,scanning velocity and scanning interval of femtosecond laser on the micro-nanostructure of the surface of 301 stainless steel was studied,which obtained two kinds of typical micro-nanostructures: periodic ripples perpendicular to the polarization direction of laser and paraboloid with double scale.The color and the absorption of light of the surfaces under different pulse energy through the optical camera and self-built light absorption detective device were studied.An optical contact angle measuring instrument was used to measure the static contact angle of the unmachined surfaces and the finished surfaces which were modified by fluorosilane and we also measured the rolling angle when the static contact angle was more than 150°.The results show: When E=0.3mJ and E=0.5mJ,the obtained surfaces of periodic ripples perpendicular to the polarization direction of laser showed color effect with angle change under natural light.When E=0.1mJ,the surfaces could not completely form periodic ripple structure,they generated lighter ablation and formed single color.When E=0.7mJ~1.1mJ,the surfaces generated severer ablation and formed different single colors.All single colors didn't change with the viewing angle.And the surfaces enhanced absorption of 660 nm red and 532 nm green light with the increase of pulse energy.The static contact angle of the machined surfaces increased with the increase of pulse energy.When E=1.1mJ,the static contact angle and rolling angle of the surfaces were 156.1° and 5°,respectively,the surfaces really realized super-hydrophobicity.In this paper,femtosecond laser was applied to the surfaces of 301 stainless steel.The surfaces of different micro-morphologies were obtained by changing the processing parameters.We also studied the optical properties and wettability of the machined surfaces.And make it possible to produce functional surfaces which can be controlled.That must expand the application of 301 stainless steel.