Study On Enhanced Anti-icing Property Of Titanium Alloy Surface With Micro-nano Structure Fabricated By Laser-based Hybrid Processing

Icing is common in nature,however,icing may cause severe accidents if it occurs in some industrial fields,in particular,the windward surfaces of airplane wings.Therefore,it is very important to study how to prevent the surface from icing.Some studies have shown that the superhydrophobicity which was found from biological surfaces has a positive effect on the anti-icing property.In this study,the relationship between anti-icing property and surface microstructure was studied with titanium alloy as the base material and biological surface microstructure as the entry point.Firstly,the biomimetic microstructure was fabricated on the titanium alloy surface by nanosecond pulsed laser ablation.Then,the effect of magnetic field on laser processing was studied.Finally,the laser textured surface is further treatment by hydrothermal synthesis with micro/nano-hierarchical structure.The effects of various processes on the surface microstructure,wettability and anti-icing properties were characterized and the mechanism was analyzed.In this work,three basic geometric microstructures were prepared on the titanium alloy surface by laser ablation,and the optimal pattern,microconical structure,was chosen by theoretical analysis and experimental verification.The size of microconical structure was tunned by adjusting the laser parameters.It is found that the size of the microconical structure can influence the solid-liquid contact state.When the surface solid-liquid contact state is Cassie-Baxter state,the surface anti-icing property is the best.After analysis,it is found that the magnetic field has a potential effect during laser processing.Under the magnetic field,the plasma and molten pool generated by laser processing will be subjected to the damping effect of Lorentz force,which will change the structure morphology.However,a very strong magnetic field is needed to improve the stability of the effect.Four kinds of micro/nano-hierarchical structures were prepared by combination of laser processing and hydrothermal treatment.The results show that the Cassie-Baxter contact state can be present on these four micro/nano hierarchical structures at room temperature.The results of anti-icing characterization shown that,at super cool temperature,it took about 3 minutes for water droplets to freeze on the smooth titanium alloy surface,and it took 30 mins longer for water droplets to freeze on the surface with microconical structure.Furthermore,on the micro/nano-hierarchical structure with nanoneedles on micro-conical arrays surface,water droplets freezing time extended more than 70 mins.In this work,the anti-icing property of titanium alloy surface was enhanced by adjusting the surface microstructure,and its potential mechanism was analyzed,which is of great significance for the preparation of new materials with anti-icing property.