Comparison of the effects of La- and Ce-rich rare earth additions on the microstructure, creep resistance, and high-temperature mechanical properties of Mg-6Zn-3Cu cast alloy

► Addition of La- and Ce-rich RE to the Mg-6Zn-3Cu alloy improved creep resistance. ► Ce-rich RE had a stronger effect on creep resistance improvement than the La-rich RE. ► La-rich RE had a stronger effect on strength improvement than the Ce-rich RE. ► The property enhancements were caused by Mg(Zn,Cu), Mg12RE and MgRE particles.