Enhanced damping capacity of nanolaminated graphene (reduced graphene oxide)/Al-Mg-Si composite

Cyclic uniaxial compression tests were carried out on micro-pillars fabricated from reduced graphene oxide (RGO)-reinforced Al-Mg-Si alloy that went through peak-ageing treatment. The composite pillars were found to have a significantly better damping capacity and improved resistance to plastic deformation as compared to the unreinforced matrix. These observations were further corroborated by the much higher damping coefficient of the composite pillars (eta = 0.3081 +/- 0.0803), almost doubled that for the alloy matrix alone (0.1560 +/- 0.0457). Site-specific TEM analysis revealed that the enhanced damping property of the composite came from a combined effect of dislocation impedance at the RGO/Al interface, the dislocation looping and cutting at the precipitates, and the formation of nano-twins in the alloy matrix upon deformation.