Development of a novel Mg–Y–Zn–Al–Li alloy with high elastic modulus and damping capacity

The novel cast Mg-1.3Y-0.8Zn-6.4Al-16.7Li (at. %) alloy showed excellent comprehensive properties including high elastic modulus of 52.9 GPa, ultra-high specific modulus (E/ρ) of 33.1 GPa cm3/g and superior damping capacity. The high elastic modulus was attributed to Li in solid solute and the formation of high modulus Al–Li compounds and Al2Y particles, and the simultaneous decrease in density due to Li addition results in the ultra-high specific modulus. At room temperature, the excellent damping capacity in the alloy was due to the presence of a large number of movable parallel dislocations. Moreover, the alloy could be classified as the high damping metal (Q−1>0.01) in the strain amplitude region. With the increasing temperature, the superior damping capacity of the alloy could be explained by dislocations movement and grain boundary gliding.