Microstructure and erosion properties of Fe-based amorphous and nanocrystalline coatings

FeCrBSiMnNbY and FeBSiNbCr amorphous coatings were fabricated by high velocity wire arc spraying process. The microstructure and phase composition of the coatings were characterized by SEM, EDAX and XRD. The formation mechanism of amorphous phase was discussed. The elevated temperature erosion behavior of the coating was also investigated. The results show that the microstructures of both coatings consist of amorphous phase and α (Fe, Cr) nanocrystalline phase. Both of the coatings are fully dense with low porosity of 1.7% and 1.2%, respectively. The coatings exhibit better erosion resistance at lower impact angles. With increasing the erosion temperature, the erosion rates of the coatings decrease. The FeBSiNbCr coating has better elevated temperature erosion resistance than that of the FeCrBSiMnNbY coating.