Surface area characterization and corrosion behavior of 90/10 copper-nickel alloy in seawater from Xiamen bay at 30 C for 56 days were investigated in this study. surface as a result of decreasing the rate of the Rabbit polyclonal to INSL3 anodic reaction . Besides, the decreased quickly from 3.812 to 1 1.056 A/cm2 after 56 days of corrosion. This were mainly due to the generation of a protective oxide film and the reduction of the Cl? attack around the alloy surface, which resulted in the reduction of corrosion rate and the homogeneous corrosion of Cu alloy. Efonidipine In addition, the increasing was concerned with the decreasing corrosion reaction caused by the reduction of anodic currents. This is identical with the experiment results of Zhu Xiao in studying the corrosion behavior of a novel Cu alloy in a salt spray environment . Generally, in the initial stage of corrosion, the surface of Cu matrix is usually relatively easy, while the halogen ions, dissolved oxygen, and corrosion products are free to diffuse on the surface of the matrix, so the corrosion of the matrix surface is controlled by activation. Cu is usually oxidized to CuO in the passivation zone, while Efonidipine Cu2O is usually oxidized in the activation zone, and chloride is usually formed by reacting with Cl? in marine environment. Cu2O has thermodynamic instability and is easy to be oxidized into copper ions. With the increasing immersion time, the corrosion product film gradually forms on the surface of the matrix and the Cu2O film became thicker, so the combination of protective oxide film and corrosion product film inhibits the diffusion of halogen ions, dissolved oxygen, and corrosion products. At this point, the anode reaction is dominated by the mass transfer process, while the cathode process remains unchanged relatively, which will result in a rise in corrosion potential. Research [55,56] show the fact that digital properties of the top film are linked to its framework and structure, so the surface area film shows various kinds of semiconductors in various potential ranges. Speaking Generally, Cu2O is an average P-type semiconductor, while high valence oxides, such as for example Fe and Ni, are N-type semiconductors. This bipolar framework can play an excellent protective function. For the B10 alloy, in the number below the flat-band potential, the area charge level of Ni and Fe oxides in the top film is within the condition of enrichment and serves as the Efonidipine conductor, as the space charge layer from the Cu oxide component is displays and depleted a P-type semiconductor. On the other hand, in the number greater than the level potential, the area charge level of Cu oxide component in the top film is within the enrichment condition, which is the same as the conductor, as the space charge level of Ni and Fe oxide is usually depleted and behave N-type semiconductor. According to the point defect model, the corrosion product film contains numerous high concentration point defects, such as metal ion vacancy and oxygen vacancy. In marine environment, on the one hand, the Cu2O on the surface of the film may occur redox transformation of copper oxide (CuO) or copper hydroxide (Cu(OH)2). On the other hand, when the corrosion product film contacts with Cl?, the oxygen vacancies in the N-type semiconductor around the outer surface of the surface film would adsorb Cl? in answer and Mott-SchottkyPair reaction would occur with Cl? to produce oxygen/metal ion vacancy pairs. The oxygen vacancies can also generate more metal ion vacancies with other Cl? reactions. Thus, increasingly more steel vacancies accumulate on the steel matrix/film user interface, isolating the matrix from the top film and avoiding the film from carrying on to develop. Furthermore, because of the elevated potential as stated above, Cl? adsorbed on the top film and led to the thickened Cu2O film, which produced a porous green corrosion item, specifically, cupric chloridehydroxide (Cu2(OH)3Cl) . When the merchandise level grows towards the internal film, the powerful equilibrium from the dissolution from the outer level is.