Study On Bright And Antirust Surface Treatment Technology For Copper And Its Alloy

Copper and its alloy are widely used in mechanical industry, chemistry, electronic industry and other industrial fields, because of its beautiful appearance and excellent performance. But their chemical property is active, and they tend to be oxygenated when exposed to air or water, especially in the environment with aggressive media. Thus, the corrosion inhibition of copper and iron has become an important research subject.Corrosive inhibition effect of enzotrizazole passivation, dodecanethiol, self-assembled layers and water-soluble epoxy resin coating were investigated. The results showed that: (1) passive films which formed in the single benzotriazole solution had no obvious performance. Adding Na2MoO4 and some surfactants into the BTA solution can improve the compactness of passivation layers and increase their anti-corrosion property; (2) dodecanethiol self-assembled layers are highly ordered, and close-packed molecular films. They act as the hydrophobic barrier layer, which effectively prevents the copper substrate from contacting corrosive ions, thereby inhibiting the copper corrosion to a considerable degree; (3) water-soluble epoxy resin coatings have anti-corrosion properties. When assembled dodecanethiol monolayer on the copper surface before epoxy resin coating formed, the performance of corrosion inhibition film can be significantly increased.The properties of anti-corrosion films were studied by humid-air accelerated corrosion test, weight-loss measurement, electrochemical polarization curves techniques and impedance spectroscopy. Corrosion phenomena of films in hot and humid environment were observed. And the change of corrosion potential, corrosion current density and charge transfer resistance on surface of layers coved electrodes in 0.51 mol/L NaCl were analyzed. The tests indicate that dodecanethiol self-assembled layers attained good inhibition effect, and it can greatly improved the corrosion inhibition performance of epoxy resin coatings.Rise and development of self-assembly technology provide a new direction of corrosion inhibitor. The result of this paper provide good reference to the application of dodecanethiol self-assembled layers to protect copper.