Microstructure and high-temperature properties of Fe-Ti-Cr-Mo-B-C-Y2O3 laser cladding coating

Fe-based composite coatings were fabricated on 5CrNiMo die steel by laser beam melting a precursor mixture of ferrotitanium, ferrochromium, ferromolybdenum, B4C and Y2O3 powders. Microstructure and properties of the coatings were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometer (EDS), resistance furnace and high-temperature tribometer. The results show that (Ti,Mo)C particles with flower-like and (Ti,Mo)B-2 with block-like shapes are in situ formed during laser cladding. Volume faction of multiple ceramic particles increases with the increasing of Y2O3. The cumulative oxidation mass of the coating with 2 wt% Y2O3 is decreased by one-third than that of the coating without Y2O3. The oxidation layer of the coating with Y2O3 is getting smooth. Meanwhile, high temperature wear volume loss of the coating with 2 wt% Y2O3 is about 40% that of the coating without Y2O3. The coating with 2 wt% Y2O3 shows a smoother wear scar and few flat grooves are observed after high temperature wear test. (C) 2020 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.