Creep properties and precipitate evolution in Al-Li alloys microalloyed with Sc and Yb

► We examine the creep behavior of Al-alloys with Li and rare earth element additions. ► These alloys exhibit threshold stresses below which no measurable creep occurs. ► Larger precipitate size and lattice parameter mismatch increase creep resistance. ► A simple parameter describes the threshold stress behavior in ternary Al-Sc-X alloys. ► The findings are explained by a recent model of dislocation-precipitate interactions.