Ultra-High Damping Capacity of Oxide Reinforced Magnesium Matrix Composites by In Situ Synthesis

In this work, in situ oxidation and particle-dispersed methods are successfully used to prepare novel oxide/Mg composites with ultra-high damping capacity starting from pure Mg as the matrix. Successful incorporation of the MgO particles into the Mg matrix is experimentally demonstrated, and the role of the oxide in enhancing the damping capacities of the composites is examined in detail. The increased damping capacity of the composites with respect to the pure magnesium is attributed to an increased dislocation density and the introduction of interface damping. In the temperature-dependent damping tests, two damping peaks P1 and P2 were found. The P1 peak is considered to be related to the interaction between dislocations and impurity atoms or vacancies. The P2 peak is considered to be caused by the grain boundaries sliding.