The Research Of Galvainc Corrosion Rule And Protection Between Carbon Fiber Composite Material And Metal

Along with the rapid scientific and technological development, fiber composite materials because of their excellent properties and designability have been received more and more attention. When the composite material contacts with metal at work,there will be galvanic corrosion happened, and the lifetime of the material could not be guaranteed. In view of this the paper makes an research on the galvanic corrosion of carbon fiber composite materials with titanium alloy, stainless steel, aluminum alloy and dead-hard steel.The effects of environmental factors such as temperature, electrolyte concentration and pH of electrolyte for the galvanic corrosion between carbon fiber composite material and metal are studied separately. Through the laboratory acceleration model, the corrosion current between carbon fiber composite material and metal is measured, and the corrosion morphology is observed by SEM. The experiments show that titanium alloy, anti-rust aluminum and stainless steel have excellent resistance to galvanic corrosion. The corrosion currents of LY12 aluminum alloy and 30CrMnSiA dead-hard steel are bigger, so they are needed for other protection treatments in the use with carbon fiber epoxy composite materials. The temperature as one of the three environmental factors has significant influence for galvanic corrosion and the corrosion current increases with the temperature significantly. The increase of the electrolyte concentration has accelerated the galvanic corrosion in a certain range, but the effect will be reduced greatly when it exceeds 7%. The pH of the electrolyte has effected on the metal differently. The galvanic corrosion current of stainless steel and titanium alloy have changed a little, the 30CrMnSiA dead-hard steel's corrosion current has increased slightly, and the corrosion current of the two kind of aluminum alloys have stepped up significantly in both acidic and alkali systems.XRD, EDS and AFM are used to studied LY12 aluminum alloy after corrosion. There is profound understanding of the galvanic corrosion process and the corrosion products for LY12 aluminum alloy with anodic oxidation. LY12 aluminum alloy is treated by micro-arc oxidation. The ceramic coating can inhibit the galvanic corrosion between aluminum alloy and carbon fiber composite materials, so the corrosion current between them has declined significantly. The systems of sodium aluminates is compared with the system of sodium silicate, the ceramic coating produced has show the better corrosion resistance in the sodium silicate system, when the power frequency is 100 Hz, and the oxidation time is 60 min.