Influence of Heat Treatment on Cold-Sprayed Aluminum Alloy Coatings Reinforced with Quasicrystals

Cold-sprayed coatings have gained prominence due to their ability to form dense, composite structures efficiently. However, the severe deformation inherent to the cold-spray process and micro forging of hard reinforcement often results in brittleness, limiting the mechanical performance of these coatings. In this study, cold-sprayed aluminum alloy AA 6061 composite coatings reinforced with quasicrystalline (QC) particles were examined, with particular focus on mitigating brittleness through heat treatment. The QC particles caused significant deformation due to the tamping effect. Heat treatments were applied at 410°C and lower temperatures around 180°C to investigate their effects on the microstructure and mechanical properties. Microstructural characterization using electron backscatter diffraction (EBSD) was employed to study texture, grain structure, deformation, and boundary types. Additionally, hardness and ductility were assessed, with ductility showing some response to the heat treatment. These structural studies revealed a shift from a highly deformed texture to a more recrystallized structure in the aluminum matrix, suggesting that heat treatment can help reduce brittleness and improve mechanical performance.