Fibre-Reinforced Nanocomposites for Spacecraft Structures – Manufacturing, Characterisation and Application

Kurzfassung

The DLR Institute of Composite Structures and Adaptive Systems has found a new and innovative way to compensate the deficits of the well-established injection technique compared to the prepreg technique with regard to material and procedure. The improvement of the composite quality by using nanocomposites was tested with the Single Line Injection technique (SLI), which was developed at the institute. Using a selected nanoparticle system, it was possible to show that the mechanical and thermophysical parameters of a established and aviation-approved, high-performance epoxy resin could be improved. A closer look was taken at an epoxy resin filled with nanosized silicon dioxide that could be provided with high stiffness and strength compared to pure resin. In addition, the resin shrinkage could be considerably reduced and thermal conductivity increased. The nanocomposite remained injectable so that there were no disadvantages in the composite manufacturing procedure with the preferred injection method. Compared to the unfilled reference resin, the density of the nanocomposites was maintained at an almost constant level (the lightweight construction aspect remained valid). These results could be transferred to fibre composite structures (GF/SiO2/epoxy matrix) that were made with the SLI technique. Particularly the significant increase of the Young’s modulus and its high linearity in the stress-strain diagram led to reduction of the inter-fibre fractures and improvement of the overall material performance in comparison to unfilled fibre composite (greater damage tolerance). The improved material properties of the fibre-reinforced nanocomposites (higher load-carrying capacity of the laminate, decrease in safety factors, reduction of the structural weight) as well as the cost-efficient manufacture of composites using the LRI technique make this new class of materials particularly interesting for use in space travel described by some examples in this paper.