Evaluation of Advanced Adhesives for Aerospace Structures

Polymer adhesives are finding increased use in panel joining applications in aircraft and aerospace structures where the applied stresses permit their use and where a uniform stress distribution is needed. One such adhesive, Hysol EA-9394™, was compared to three other formulations in this study. The new formulations were Hysol EA-9396, Hysol EA-9396 filled with nickel nanofibers and mixed by machine (Jamesbury Blender), and Hysol EA-9396 filled with nickel nanofibers and hand mixed in the laboratory. The comparison consisted of measuring shear lap strengths of aluminum test pieces bonded together with the candidate adhesives. The mechanical tests were supplemented by a Weibull analysis of the strength data and by a visual inspection of the failure mode (adhesive/cohesive). The lap shear strengths (fracture stress values) of all three Hysol EA-9396 adhesives were greater than that of the baseline Hysol EA-9394 polymer.