| A large number of galvanic corrision phenomena exist in industrial production and daily life.When different materials are in electrical contact,a potential difference generates between the materials,which accelerates corrosion of the anodic material and shortens its service life.Therefore,the galvanic systems based on AA2024-T3 and two other materials(carbon fiber-reinfored polymer and titanium alloy)were designed and explored.The main contents are as follows:Firstly,the AA2024-T3 alunium alloy and carbon fiber-reinfored polymer galvanic system was designed.The corrosion of the system was investigated by zero resistance ammeter and scanning vibrating electrode technique.The effects of several factors(Cl~-concentration,area ratio of two materials,pH and temperature)on the galvanic system were investigated.The results show that the system with a solution pH of 10 exhibits higher galvanic current and surface current density than the solution pH of 4 and 7.Comparing with the case where the area ratio of carbon fiber-reinfored polymer to AA2024-T3 aluminum alloy is 1:1 and 1:5,the system shows higher galvanic current when the area ratio of carbon fiber-reinfored polymer to AA2024-T3 aluminum alloy is 5:1,and it exhibits similar surface current density under the three conditions.Comparing with the concentration of Cl~-is0.17mol/L and 0.6mol/L,the system shows higher galvanic current when the concentration of Cl~-is 1.2mol/L.Comparing with the experimental temperature is 25°C and 40℃,the system shows higher galvanic current when the experimental temperature is 60°C.The results of scanning electron microscopy and X-ray photoelectron spectroscopy show that the organic cerium can form stable protective film on the surface of carbon fiber-reinforced polymer,which protect the system.Secondly,the AA2024-T3 aluminum alloy/TC4 titanium alloy galvanic system was designed and explored.The effect of several factors(Cl~-concentration,area ratio of two materials,pH,temperature)on the galvanic system was investigated.The results show that the system with a solution pH of 4 exhibits higher galvanic current and surface current density than the solution pH of 7 and 10.Comparing with the the area ratio of TC4 titanium alloy to AA2024-T3 aluminum alloy is 1:1 and 1:5,the system shows higher galvanic current when the area ratio of TC4 titanium alloy to AA2024-T3 aluminum alloy is 5:1,and it exhibits higher surface ion current density when the area ratio of TC4 titanium alloy to AA2024-T3 aluminum alloy is 5:1 and 1:5.Comparing with the concentration of Cl~-is 0.17mol/L and 0.6mol/L,the system shows higher galvanic current when the concentration of Cl~-is 1.2mol/L.Comparing with the experimental temperature is 25°C and 40℃,the system shows higher galvanic current when the experimental temperature is 60°C.The corrosion inhibition effect of organic cerium salt on the system was investigated.The results show that the organic cerium salt can form stable protective film on the surface of TC4 titanium alloy,which can relieve the galvanic corrosion of the system effectively. |
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