Investigation of the Microstructure and Wear Properties of Laser Clad Al-Si Coatings Containing Different Y2O3 Contents

Y2O3-reinforced Al-Si alloy coatings were prepared on the surface of a Mg alloy by the laser cladding technique. The microstructure, hardness, and wear resistance of the coatings were analyzed using an X-ray diffractometer, a scanning electron microscope, an energy spectrometer, a Vickers hardness tester, and a friction wear tester. The effect of different additions of Y2O3 on the microstructure and properties of the coatings was investigated. The results indicate that the addition of Y2O3 leads to a significant refinement of the grain size and a denser microstructure of the coatings. Coatings with a high Y2O3 content provide superior hardness and wear resistance. With a Y2O3 content of 7.5 wt.%, the coating exhibits the finest grain size, highest hardness, and smallest wear volume. Excessive amounts of Y2O3, however, cause a reduction in the surface properties of the coating.