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Fabrication Of Superhydrophobic Surface On S45C Steel And Properties Of Anti-corrosion And Tribology

Posted on:2017-03-10Degree:MasterType:Thesis
Country:ChinaCandidate:H M ZhangFull Text:PDF
GTID:2271330509452451Subject:Materials science
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Steels are widely used in mechanical industry because of their low cost and easy cutability. While their tribological and anti-corrosion properties are poor and directly affect their service life. Although the traditional methods can protect metals from wearing and corroding, while they need special equipment and sometimes damage the environment and do harm to our health. In recent years, inspired by the “lotus effect”, superhydrophobic surfaces that contact angle greater than 150 ° have attracted significant interest. It can prevent water penetrating into the substrates and their textured surface can also reduce the real contact area and then have a potential application in anti-corrosion and tribology. Therefore, in this paper, we developed three simple and economical methods to fabricate superhydrophobic surfaces with excellent anti-corrosion、friction-reducing and abrasion resistance properties on S45 C steel. The main results are shown as following:(1)The textured steel surface with island-like protrusions, micro-pits and nano-flakes was fabricated by a simple chemical etching method. And we analyzed the formation mechanism of multiscale structures. After modified by low-surface-energy molecules, the steel had superhydrophobicity. The potentiodynamic polarization test indicated that the as-prepared surface had excellent corrosion resistance that can provide effective protection for the steel substrates. The tribological test showed that friction coefficient maintained 0.11 within 6000 s. And the surface still kept superhydrophobicity after abrasion for 100 cm under the pressure of 500 g, showing a good friction-reducing and wear resistance performance.(2)The superhydrophobic steel surface with three-dimensional flower-like MoS2 was fabricated by hydrothermal method. With subsequent surface modification, the MoS2 microspheres exhibited superhydrophobicity and superoleophobicity. The reaction time on the wettability and microstructure of MoS2 was investigated. The results indicated that the corrosion potential increased and corrosion current density decreased compared with untreated samples. And we further study the change of the water contact angle by immersing the superhydrophobic samples in 3.5wt%NaCl solution. Moreover, the tribological test showed that the friction coefficient decreased from 0.45 to 0.15 that exhibited better antifriction property.(3)The micro-protrusions and nano-rod lotus-like nickel coating has been fabricated via electroless plating of nickel. The superhydrophobic S45 C steel was obtained after modification. The wettability, tribology and anti-corrosion performances were discussed to study the relationship with the plating time. The results indicated that the surface layer become uniformly and the thickness close to 7μm after plating for three hours. And the corrosion potential of treated samples shifts markedly to positive direction by contrast to the untreated substrates. Moreover, it also has superior tribological properties. The friction coefficient was about 0.2 and it still kept superhydrophobicity after abrasion for 160 cm under the pressure of 500 g.
Keywords/Search Tags:S45C steel, Textured, Superhydrophobicity, Tribological property, Anti-corrosion property
PDF Full Text Request
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