Effect of Nanosecond Laser Treatment Parameters on Surface Wettability Behaviour of Pure Aluminium

Abstract

In this study, a method of preparing stable superhydrophilic surface on aluminum plate by nanosecond laser is presented. The influences of different laser processing parameters on the wettability of aluminum plate and the effect of preservation temperature on the conversion rate of aluminum plate from superhydrophilic to superhydrophobic after laser ablation were studied. It is demonstrated that the microstructure formed by different laser processing parameters has certain influence on the hydrophilic property of aluminum plate, such as the lower the scanning interval and scanning speed, the easier it is to form a superhydrophilic surface. In addition, the storage temperature has a significant effect on the change of surface contact angle with time. The samples stored in the average temperature of 0°C in the atmospheric environment have an average contact angle of 18.7 °in 60 day after laser treatment, which has always maintained a good hydrophilicity. However, the samples heated 3 hours in the temperature of 150 °C appears the hydrophobicity with an average contact angle of 156.3 The mechanism of wettability transition was expounded, and a method to maintain the superhydrophilic durability of metal surface was proposed in this paper.