Electrochemical investigation of galvanic corrosion between aluminum 7075 and glass fiber/epoxy composites modified with carbon nanotubes

摘要

We investigate whether the presence of carbon nanotubes in previously non-conductive composites may cause galvanic corrosion. We focus on aluminum 7075 alloy and glass fiber-reinforced polymers (GFRP), where the epoxy resin is modified with multi-walled carbon nanotubes (MWCNTs). Whole aluminum bars were bonded with MWCNT/GFRP in a co-cure, or were connected electrically with the composite through a galvanic cell.The investigation includes characterization of the treated and baseline epoxy resin, high humidity tests at room temperature, full immersion tests in an aggressive environment, and standard galvanic coupling tests in an aggressive environment.Results show that coupling MWCNT/GFRP samples with aluminum 7075 causes approximately doubled corrosion rate and mass loss rate compared to baseline GFRP samples. We envision that this work will impact the research community and indicate the need of careful coupling selection and careful surface treatment between nanomaterials and conventional materials, since the ability to monitor damage in situ is very desirable.