Corrosion of Aluminum Alloys-Polymer Matrix Composite Interfaces

Abstract

The accelerated corrosion of several carbon-fiber (CFRP) and E-glass/epoxy (GFRP) composite laminated aluminum alloys [i.e., Al 1100-H14, Al 5456-H116 (non-sensitized), Al 5456-H116 (sensitized), & Al 7075-T6] was studied to characterize the interfacial corrosion between the composite and aluminum substrate. Samples were placed in the Cyclic Corrosion Testing Chamber (CCTC) for accelerated corrosion testing per the GM 9540P Test Procedure for 1-week, 2-weeks, & 3-weeks exposure periods. The samples were then adhesion strength tested and analyzed with a SEM & EDX system to determine the loss (if any) of the composite laminate adhesion to their respective aluminum substrates and the presence of corrosion products that may have formed in the aluminum substrates and composite laminate interfaces. The decay in adhesion strength was correlated to the amount of corrosion at the interface that was dependent on the type of composite and aluminum alloy.