High creep resistance behavior of the casting Al–Cu alloy modified by La

The creep resistance of casting Al–Cu alloy modified with La is almost 3–5 times higher than that of the unmodified one. La addition results in the formation of (i) Al 11La 3 phases in the grain boundaries and (ii) spaces among the dendrites in the modified casting Al–Cu alloy. The Al 11La 3 phases exhibit good thermal stability, inhibiting grain boundary migration and dislocation movement during the creep process.