The Function Study Of Metal Titanium Based On Femtosecond Laser Processing

Femtosecond laser bionic micro/nano machining has always been a heat topic in the field of materials research.Base on the advantages of the extremely short pulse,peak value power and the effect of processing without thermal influence,femtosecond laser is widely substituted for the complex physical and chemical method.In this paper,advanced ultra-fast femtosecond laser micro/nano technology was used to irradiate titanium sheets.The processing parameters,such as pulse energy,scanning velocity and the distance between the adjacent laser beam,has been regulate to prepare specific micro/nanostructures with special functions.The thesis mainly includes the following two parts:?1?A kind of three-level cobblestone-like anatase TiO₂ microcone arrays were fabricated on titanium sheets by femtosecond laser-induced self-assembly.This three level structure consisted of cobblestone-like features?15 25 ?m height and 20 35 ?m diameter?, 460 nm ripple-like features,and smaller particles?10 500 nm?.The formation of microcone can be ascribed to the interaction of alternant laser beams ablation.The TiO₂ surfaces display dual-responsive water/oil reversible wetting via heat treatment and selective UV irradiation without fluorination.It is indicated that three-level scale surface roughness can amplify the wetting character of Ti surface,and the mechanism for reversible switching between extreme wettability is caused by the conversion between Ti-OH and Ti-O.Moreover,the double-faced superhydrophobic and double-faced superhydrophilic Ti samples were constructed,which exhibited stable superhydrophobicity and underwater superolephobicity in water-oil solution respectively even when strongly shaken.Finally,we presented the hybrid-patterned TiO₂ surface and realized reversible switching pattern wettability.?2?Ultra-thin titanium foils with micro-scale pores were fabricated by femtosecond laser microdrilling technique.The effect of pulse energy on the diameter of titanium pores was researched in detail.It is found that the size of micropore is gradually increased with the increase of pulse energy.Moreover,we could obtained two organic solvents with different wettability after fluorination treatment,which contribute to the separation and collection process of organic mixed solution.