Enhanced Damping Capacities of Mg–Ce Alloy by the Special Microstructure with Parallel Second Phase

Microstructure evolution and damping capacities of Mg–Ce binary alloys with three different Ce contents (0.5, 1, or 2 wt%) have been systematically investigated in this work. Numerous fine parallel second phases in Mg–2Ce alloy are obtained, as well as a large number of dislocations around them, but few dislocations appear around the reticular second phase in the Mg–1Ce alloy. Among the three alloys, two internal friction peaks (P1 and P2) are detected at about 78 and 167 °C in both the Mg–0.5Ce and Mg–1Ce alloys. In addition, the alloy with special parallel second phase structure exhibits excellent damping capacity in both strain amplitude and temperature-dependent regions. These results may be ascribed to the stress concentration and the formation of abundant parallel and uniform dislocation configurations in the α-Mg matrix without the influence of crystal orientation. The obtained results may provide a novel idea to prepare high-damping magnesium alloys by tailoring their microstructure.