Study On Ice Friction Properties Of Biomimetic Hydrophobic Microstructures On Metal-Based Materials

Ice friction is one of the most common natural phenomena in northern winter.The study of ice friction has important significance in the fields of road safety,glacier movement,ice movement,offshore structure design and ice breaker.Based on the characteristics of natural superhydrophobic formation mechanism and nanosecond laser processing technology,this paper designed a lotus-like lotus root groove composite microstructure on stainless steel surface.By analyzing the basic principle of laser processing and the influence of laser processing power,repetition pulse number and scanning structure spacings on the microstructure of metal surface,the control of the microstructure and shape of metal surface were realized,and a kind of lotus root groove composite structure was constructed.It had been found that the laser scanning speed,laser processing power,number of repetitive pulses,and laser scanning pitch processing parameters affect the surface topography of the microstructure,which in turn affects the surface contact angle.The laser scanning speed of 200mm/s,the processing power of 10 w,the number of repeated pulses of 15 times,and the scanning interval of 0.05 mm can realize the construction of the lotus root groove composite structure.The super-hydrophobic surface of nanosecond laser processing had a high adhesion,and the modification of low surface energy materials can change the adhesion of the surface.The surface after processing was initially hydrophilic and changes to superhydrophobicity after contact with air for a period of time.Through mechanism analysis,it was found that the increase of the ratio of C/Fe on the surface of stainless steel was the cause of the conversion from hydrophilic to hydrophobic.After the modification of low surface energy,the static contact angle changed little,but the dynamic contact angle changed greatly,and the rolling angle reached 6.4°.Modified surfaces showed better self-cleaning performance and bounce performance.Microstructure was the main reason for the superhydrophobicity of stainless steel surfaces,and the change of material composition was the main factor affecting its adhesion.The test results showed that the ice friction coefficient of stainless steel surface was related to hydrophobicity,adhesion and sliding speed.The greater the sliding speed,the better the hydrophobicity,and the lower the adhesion,the smaller the coefficient of friction.The high sliding speed increased the amount of water film formed,while the superhydrophobic surface reduced the wetted area of the material,reduced the accumulation of capillary bridges,and caused the ice friction to be in the mixed friction phase.Low adhesion reduced surface and water viscosity,prevented the formation of more capillary bridges,and thus lowered the average coefficient of friction of the surface.