纳秒激光制备超疏水TC4钛合金表面的抗结霜性能

Frost Resistance of Superhydrophobic TC4 Titanium Alloy Surface by Nanosecond Laser

采用纳秒激光对TC4钛合金表面进行刻蚀,然后放入电热干燥箱内烘烤,研究了钛合金表面的浸润特性、微观结构及抗结霜性能。结果表明:在100 W激光功率下纳秒激光刻蚀和烘烤处理后钛合金表面接触角超过160°,而滚动角小于5°,具有非常好的超疏水性能,钛合金表面呈纳米级的凹坑、凸起和规则球状结构;激光刻蚀钛合金表面经烘烤后同时满足了粗糙微观结构与低表面能的条件,表面的浸润特性从超亲水状态转变为超疏水状态;在-15℃下激光刻蚀和烘烤后的超疏水钛合金表面9μL水滴完全结冰所需时间为360 s,比未激光刻蚀钛合金延长了2倍以上,且水滴完全结冰后仍能保持大于130°的接触角;在-15℃恒湿条件下持续冷冻10 min后超疏水钛合金表面只出现了零散的小颗粒霜晶,而未激光刻蚀钛合金表面密集分布着大量小颗粒霜晶。

The surface of TC4 titanium alloy was etched by nanosecond laser,and then baked in an electrothermal drying oven.The wetting characteristics,microstructure and frost resistance of titanium alloy surface were studied.The results show that after nanosecond laser etching at 100 W laser power and baking,the contact angle of titanium alloy surface exceeded 160°,and the rolling angle was less than 5°,indicating the surface had superhydrophobic properties.The surface of titanium alloy presented nano pits,bulges and regular spherical structures.After baking,the surface of laser etched titanium alloy met the conditions of rough microstructure and low surface energy,and the wetting characteristics of the surface changed from superhydrophilic state to superhydrophobic state.The time required for complete freezing of 9μL water droplet on superhydrophobic titanium alloy surface at-15℃was 360 s,which was more than 2 times longer than that of titanium alloy without laser etching,and the contact angle of water droplets could still be maintained greater than 130°after complete freezing.After being frozen for 10 min at-15℃with constant humidity,only scattered small frost crystals appeared on the superhydrophobic titanium alloy surface,while a large number of small frost crystals were densely distributed on the surface of titanium alloy without laser etching.