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The composite studied here consisted of a geopolymer matrix reinforced with quasicrystal powders. Quasicrystals are complex metal alloys with atypical structures. Due to their physical, mechanical and surface properties, quasicrystals have been widely studied. Nowadays quasicrystalline powders are proposed to be incorporated in ductile matrices. The geopolymers are inorganic polymers with excellent thermal performance and interesting adhesive properties. The quasicrystalline alloys were prepared by induction melting the constituents under argon atmosphere in a water-cooled copper crucible. In this work the adhesion of composites with 5, 10 and 15% of quasicrystal powder in aluminum joints was investigated. In addition, the influence of the curing time was taken in to account and tests were performed in samples with 7 and 28 days of cure. The results indicate an improvement in adherence with the inclusion of quasicrystal. The best adherence was obtained when the curing time was 28 days.

The geopolymer although being a recently discovered material, it is already present in many industrial sectors. This range of applications is due to the commitment of the scientific community to understand and manipulate the material, seeking a contribution in this regard, it has produced geopolymer matrix composites with quasicrystalline and reinforcement, Al62,2Cu25,5Fe12,3 in the proportion of 10%, 20% and 30% by volume. These composites were obtained by manual production and heat treated at 400 º C for two hours. The characterization was made with the aid of scanning electron microscopy (SEM) and x-ray diffraction (XRD). Diffractograms of composites without heat treatment showed characteristic peaks of the phases present in the matrix and reinforcement. For the composites with heat-treated, it was observed that besides the phases mentioned above the presence of diffraction peaks possibly associated phase silica sodium aluminate. The composite showed good interface quasicrystal / geopolymer, showing the existence of a phase with lamellar morphology in the treated material.

Quasicrystals (QC) are materials that exhibit good surface properties such as high hardness, low surface energy, low friction coefficient, and good resistance to oxidation and corrosion. Despite these properties, QC alloys are highly brittle, discouraging their uses in applications requiring mechanical stresses. Hence, the development of composites using quasicrystalline materials as reinforcement to ductile matrices is an interesting alternative. In this work, Al-Cu-Fe quasicrystals were used as a reinforcement to epoxy resin in order improve adhesion with metallic substrates. Adhesive properties were evaluated by single lap joint (SLJ) tests and the QC=epoxy interface was analyzed by scanning electron microscopy (SEM). Aluminum, copper, and iron, individual elements, were used to investigate the contribution of each element to the adhesive. Results show that it was possible to significantly enhance adhesion properties when 25% QC was added to epoxy and that the effect of QC amount on SLJ bond strength did not follow a linear trend. Moreover, the contribution of each alloying element was important to explain the influence of QC addition on adhesive properties of the epoxy-based composites.

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