Magnesium-based nanocomposites

Abstract

The Mg micropowder was generated by gas atomisation of a magnesium melt with argon. The ceramic nanoparticles (SiC, ZrO2, Al2O3) and carbon nanoparticles were generated by laser-induced gas phase reaction in a flow reactor. The Mg materials were mixed and ball milled with nanoscaled ceramic powder and then was hot extruded. The mechanical properties of new materials were investigated by tensile test at temperatures between room temperature and 300°C at a constant initial strain rate. The flow stress is significantly influenced by temperature. The nanocomposites exhibit high-damping characteristics. The damping was measured as the logarithmic decrement of the free decay of the vibrating nanocomposite beam. At lower strains, the logarithmic decrement is practically independent of the strain amplitude, whereas at higher strains the decrement increases with increasing strain amplitude. The volume fraction and the kind of reinforcement influence the value of the logarithmic decrement and its temperature dependence.