不锈钢表面复合微结构的冰摩擦性能

Ice Friction Properties of Composite Microstructures on Stainless Steel Surface

目的探究不锈钢表面复合微结构的冰摩擦性能。方法采用纳秒光纤激光器在不锈钢表面构建类莲藕型沟槽复合结构,并对不同润湿性、粘附性和摩擦速度下的冰摩擦性能进行了观测与分析。结果微米-亚微米级复合结构是不锈钢表面超疏水高粘附的主要原因,热处理消除了样件表面的时效性,化学修饰实现了超疏水由高粘附性到低粘附性的转换。温度的变化改变了水滴在样件表面的接触状态。在滑动速度为0~1mm/s、载荷为2N的条件下,随着滑动速度的增加,疏水性越好、粘附性越低的表面具有较小的摩擦系数,因为摩擦热产生的水膜形成了润滑层,使冰摩擦处于混合摩擦阶段,降低了摩擦阻力。但过多的水膜会形成大量毛细管桥,增大阻力。结论超疏水表面由于其独特的类莲藕复合结构,减小了材料的接触面积,降低了毛细管桥的积聚,从而降低了冰摩擦表面的平均摩擦系数。同时,低粘附性降低了表面与水的粘滞性,阻止了更多毛细管桥的形成,是影响冰摩擦系数的另一重要因素。

In order to explore the ice frictional properties of superhydrophobic composite structure surfaces,a nano-second laser system was used to construct a lotus-like groove composite structure on the surface of stainless steel.The properties of ice friction under different wettability,adhesion and friction speed were observed.It can be shown from the results that the micro-submicron composite structure is the main reason for super-hydrophobic high adhesion of the stainless steel surface.Heat treatment eliminates the timeliness of the sample surface,and the chemical modification realizes super-hydrophobic low adhesion.The temperature changes the contact state of the water droplets on the surface of samples.Under the condition of 0~1 mm/s sliding speed and 2 N load, the surface with larger sliding speed, better hydrophobicity and lower adhesion hassmaller friction coefficient. This is because the water film produced by friction heat forms a lubricating layer, which makes theice friction in the mixed friction, thus reducing the friction resistance. However, too much water film will form a lot of capillarybridge, and increase the resistance. Because of the unique lotus-like micro-structure on the surface of superhydrophobic surface,both the wetting area of the material and the accumulation of capillary bridges are reduced, thus the average friction coefficientof the ice friction surface is reduced. At the same time, the low adhesion reduces the viscosity between the surface and water andprevents the formation of more capillary bridges, which is another important factor affecting the ice friction coefficient.