Rare-earth La2O3 modification of laser-clad coatings

The effect of rare-earth La2O3 on laser-clad coatings has been studied. For this purpose, nickel-based alloy powders with different contents of La2O3 were laser-clad on to a steel substrate. The clad coatings were examined an d tested for microstructural features, microhardness, inclusions and phase composition. The results are compared with those for coatings without La2O3 . The comparison indicates that additions of La2O3 refine the microstructur e of the clad, and the coating increases its microhardness. Moreover, the w ear resistance and corrosion resistance of the clad coatings are also enhan ced. (C) 1998 Kluwer Academic Publishers.