Study of fly ash-based flux effects on microstructure and wear of TIG-cladded Ni-based composite coating

Abstract

The Al2O3-TiB2 reinforced nickel-based composite coating was prepared by the active argon arc cladding technology from nickel based alloy, Al2O3 and Al-TiO2-B2O3 feedstock powders, applying mixture of aluminium containing fly ash, titanium, SiO2, B2O3 and La2O3 as a flux. Microstructure, phase composition, hardness and abrasive wear of the coating were studied. The results show that the number and intensity of the diffraction peaks of Al2O3, TiB2 and (Fe, Cr)23C6 in the active argon arc cladded in the cladded layer are significantly increased, moreover the new phases such as Fe2B, 3Al2O3-2SiO2 (mullite phase), Ni3Si, Fe17Al40Si10 are also formed. The melt depth and width of the active cladding are 5.25 mm and 8.26 mm respectively. The surface hardness of ordinary cladded layer and active cladded layer increased by 4.11 times and 4.37 times respectively, to be compared with the substrate. The abrasion wear resistance of the ordinary cladded layer and fly ash active cladded layer is 6.96 times and 7.72 times higher, than that of the substrate, respectively. Keywords: Fly ash, Argon arc cladding technology, Abrasive wear resistance