Magnetic properties of HVOF thermally sprayed coatings obtained from nanostructured powders

The development of amorphous and nanocrystalline materials has attracted significant interest in the field of new materials design. Indeed, the different properties, especially the magnetic properties of materials, are largely enhanced when the size of crystallites becomes nanometric. Besides, the presence of nanocrystalline structure implicates a macroscopic behaviour fairly different from the conventional microstructured materials. s context, the microstructure and magnetic properties deposits obtained by High Velocity Oxy-Fuel (HVOF) from nanostructured FeSi-based feedstock powders were investigated. Ultra fine grain FeSi-based coatings were synthesised. X-ray analysis shows the formation of amorphous and nanostructured phases in some coatings. Mِssbauer measurements confirmed also the presence of the amorphous phase. Magnetic measurements revealed a ferromagnetic character for all the coatings. Though the presence of nanostructure has a significant effect to modify magnetic properties, the results also indicated that the boron, niobium and copper incorporated in the feedstock-milled powders have little effect on these properties.