| Abstract Scope |
Microstructure and mechanical properties are studied for five arc-melted, coarse-grained intermetallic alloys with rare-earth (RE) elements and Al: binary Al11Ce3 and Al11La3, ternary Al11(Ce0.75La0.25)3 and Al11(Ce0.5La0.5)3, and quaternary Al11(Ce0.54La0.27Nd0.19)3. All alloys display a single phase, with a solid solution of RE elements Ce, La, Nd on the Ce sublattice of Al11RE3, in disagreement with the Thermo-Calc’s prediction of Ce and (La, Nd) segregating into separated Al11RE3 compounds. As La concentration increases, the orthorhombic Immm-structured α-Al11RE3 phase’s lattice parameters increase and the α-β phase transformation temperature decreases. These compounds show similarities in their high hardness (4.1-4.3 GPa), low fracture toughness (0.48-0.65 MPa m1/2), and lattice mismatch on the Al-Al11RE3 interfaces, indicating their comparable strengthening and coarsening resistance effects in Al-RE-based eutectic alloys. Therefore, they are potential economically and environmentally favorable alternatives to the Al11Ce3 compound in current Al-Ce alloys. |