Rare-earth oxides such as cerium oxide, lanthanum oxide, and yttrium oxide can improve laser-cladded metal coatings by refining grains, purifying the molten pool, strengthening interfaces, and altering solidification behavior. The review finds that these effects can increase hardness, wear resistance, corrosion resistance, and crack resistance, although performance depends strongly on additive concentration, particle size, alloy system, and processing conditions.
