Microstructure and mechanical properties of Mg–Al-based alloy modified with cerium

Mg90Al10–xCex with x=0, 1, 3 and 5 (at%) have been prepared by copper mold casting and the influence of Ce on the microstructure and mechanical properties have been investigated. The addition of 1% Ce decreases the volume fraction of the γ-Mg17Al12 phase and with the further increase of Ce to 3% and 5%, the γ-Mg17Al12 intermetallic disappears completely with the formation of the Al11Ce3 and Al2Ce intermetallic phases. The room temperature compression tests show that Ce addition significantly improves the room temperature mechanical properties. For example, the alloy with 5% Ce displays a strength of 448 MPa compared to 318 MPa of the binary Ce-free alloy along with appreciable plasticity of about 9%. This improvement is due to grain refinement as well as to the precipitation of the Al11Ce3 and Al2Ce strengthening phases.