SURFACE-HARDENED ALUMINUM-RACE EARTH ALLOYS AND METHODS OF MAKING THE SAME

Embodiments of surface-hardened aluminum-rare earth alloys and methods of making the alloys are disclosed. In some embodiments, the alloy comprises aluminum and 4 wt% to 60 wt% of a rare earth component X having a maximum solid solubility of ≤ 0.5 wt% in aluminum. The surface-hardened alloy component has an alloy bulk portion and a hardened alloy surface portion. At least a portion of the hardened alloy surface portion has a Vickers hardness that is at least 30% greater than a Vickers hardness of the alloy bulk portion.