Aerogel-honeycomb sandwich composites based on resorcinol-formaldehyde and silica

Abstract

Composites consisting of aerogels are lightweight materials with possible applications in many fields including the aerospace, automotive, and building sectors. In that context, we have previously demonstrated how aerogels derived from resorcinol-formaldehyde and silica can be mechanically reinforced using aramid-, paper-, or aluminum-based honeycomb structures as matrix in the sol-gel process. This poster describes efforts to produce sandwich materials using such honeycomb-aerogel-composites as core material, and metal sheets as coating. Qualitative studies regarding different adhesives and suitable joining methodology for aerogel-honeycomb composites, as well as joining of core composite and aluminum sheets of varying thickness are described. The resulting sandwich materials were characterized in terms of their thermal and mechanical behavior. More specifically, the thermal conductivity of sandwich materials and core components were determined using a heat flow meter or transient plane source technique, respectively. Regarding mechanical properties, compressive, tensile, shear, and bending tests were performed. The combined results allow for the design of aerogel composite sandwich materials with a balanced trade-off between thermal and mechanical properties. The studies presented herein will guide current and future efforts directed to the production of generic parts for automotive applications.