Damping behaviors of magnesium matrix composites reinforced with Cu-coated and uncoated SiC particulates

Magnesium matrix composites reinforced with Cu-coated and uncoated SiC particulates were fabricated by a powder metallurgy and hot extrusion process, their damping behaviors were studied in this paper. The results show that, pure Mg excels the composites in the damping capacity at low temperature; when the temperature increases to about 75 °C, the damping of the uncoated composite will exceed that of pure Mg; a further increase to 250 °C will also cause a superior damping for the coated composite to that of pure Mg. Especially to note that, one relaxation damping peak appears in the damping spectra of composites, and besides, the damping peak in the coated composite is less pronounced than that in the uncoated one, which is related to dislocation damping mechanism.