Synergetic effect of Er and Zr on the precipitation hardening of Al–Er–Zr alloy

The precipitation hardening of dilute Al–Er, Al–Zr and Al–Er–Zr alloys was investigated by microhardness measurements and transmission electron microscopy. The Al–0.04Er (at.%) alloy obtains its maximum aging hardness of 400 MPa due to the precipitation of Al3Er. The Al–0.04Er–0.08Zr obtains a maximum hardness of 560 MPa, which is significant greater than that of the Al–Er and Al–Zr alloys. The synergetic effect of Er and Zr on the precipitation hardening of Al–Er–Zr alloys is discussed.