Fabrication Of Superhydrophobic Surface On Aluminum Substrates And Its Research Of Corrosion Resistance In Seawater

Over recent years, owing to the inspiration of bionics and outstanding performance in anti – contamination, self-cleaning, anti-icing and anti-corrosion, the super-hydrophobic surface get great attentions and widely used in construction, manufacturing and agriculture. With the rapid development of oceanic industries, exploiting marine resources and alleviating resource pressure need to be solved among above problems, Marine corrosion is a main factor that hinder the development of marine industry. In this paper, we packed with the super-hydrophobic surface and anti-marine corrosion together to slow down the substrate’s corrosion in seawater. On the other side, the mirco-nano structure on super-hydrophobic surface is easily be destroyed which influence hydrophobic properties, so it has become a critical factor to enhance the mechanical strength and to improve the tribological properties.Aluminum was used as substrates in this paper due to its wide application in the marine industry. In view of generating super-hydrophobic aluminum-based substrates, the micro/nano structure was created by anodization or chemical etch and low surface free energy is needed, the other got by modified. The anti-corrosion resistance was investigated by CHI660 E electrochemical workstation, the surfaces mechanical durability was tested by UMT. The main results are showed as the following:(1) The super-hydrophobic film was created by anodization, etched by 20g/L chromic acid solutions and modified by myristic acid on aluminum substrate, which contact angle was above 150° and rolling contact was 1°. The super-hydrophobic sample got a great improvement in corrosion resistance and inhibition rate reaching 99.99%. Tribological properties were tested under 0.5N load by UMT with steel ball. The results showed that the substrate was protected by super-hydrophobic film that life is more than 1800 seconds. Mechanical hydrophobic durability was tested under 0.1N load by UMT with metallographic polishing cloth. After 2400 wear cycle, the substrates still remained hydrophobic.(2) The super-hydrophobic film was prepared by etching in Cu Cl2 solutions, modified by heated 20 h, melted Myristic, heated 20 h then melted myristic respectively. The results showed that contact angle created by different modified ways was reached 146 °,152 °,154 ° and rolling contact was 8 °,7 °,4 ° respectively, through anti-corrosion resistance test, we got the data that inhibition rate reached 26.88%,98.06%,99.00% respectively. Tribological properties and mechanical hydrophobic durability were different due to different modified methods; the substrate modified by melted myristic got the most excellent tribological properties which COF remain 0.4 over 1800 seconds. Mechanical hydrophobic durability test showed that heated 20 h then melted myristic sample> melted myristic sample> heated 20 h sample, samples still had hydrophobic property after 2400 wear cycle.In a word, this thesis prepared super-hydrophobic surface with the combination of anodization, chemical etch and low surface energy coating. Prepared substrates showed excellent anti-corrosion resistance and good mechanical hydrophobic durability which made aluminum got certain significance in anti-seawater corrosion area.