Metal Corrosion Behavior And Corrosion Mechanism Of Vapor Phase Corrosion Inhibitor Under Thin Electrolyte Layer In The Presence Of Space Electric Field

The purpose of this study was to investigate the influence of spatial electric field on metal corrosion behavior and inhibition mechanism of vapor phase inhibitor（VCIs）. To simulate the corrosive environment of electronic systems, a constant temperature and humidity airtight device was designed in which electric field could be applied. The corrosion behavior of carbon steel and copper and the inhibiting behaviors of cyclohexylamine carbonate（CHC） and benzotriazole（BTA） had been researched in this research under space electric field.The corrosion behavior of carbon steel and copper, CHC inhibition mechanism on carbon steel and BTA inhibition mechanism on copper was investigated using potentiodynamic and electrochemical impedance spectrum measurements（EIS） in the presence of electric field which the intensity was 1.5×105V/m. The surface was characterized by scanning electron microscopy（SEM）, X-ray photoelectron spectroscopy（XPS）. Materials Studio6.0 software was used to calculate the quantum chemical parameters of VCIs. The quantum chemical parameters were calculated that are closely related to the corrosion efficiency of CHC and BTA, including the E_HOMO（energy of highest occupied orbital）, E_LUMO（energy of lowest unoccupied orbital）, energy gap(?E=E_LUMO–E_HOMO), dipole moment（μ）, charge distribution and bond length.The results showed that the corrosion behavior of carbon steel and copper has not changed obviously under the space electric field, which shows that the corrosion of carbon steel and copper could not be affected by the spatial electric field. When the electric field was not applied, CHC protected the carbon steel well but CHC has almost completely lost the corrosion inhibition effect under the condition of space electric field. Quantum chemistry calculation showed that the quantum chemical parameters of CHC will change with the change of the electric field intensity, the electric field affected the properties of the CHC, such as electron donating ability, adsorption capacity, charge density, so as to decrease the corrosion inhibition efficiency.Unlike CHC, regardless of whether or not the application of space electric field BTA protected the metal copper well. BTA with benzene ring structure and can form very stable polymer film[BTA-Cu（I）]n on the surface of the copper. There was no significant effect of the spatial electric field on the corrosion inhibition of BTA. The quantum chemical parameters of BTA under different electric field almost no change, which also confirmed that the space electric field will not affect the corrosion inhibition of BTA.NaNO₂ could effectively prevent corrosion of carbon steel, but the horizontal electric field decreased the corrosion inhibition efficiency. Due to sodium nitrite is oxidized corrosion inhibition agent and NO₂^- with negative charge. Under the horizontal direction electric field, the nitrite ions migrated to the positive side of the electric field.