Microstructure and magnetic properties of Fe–Si-based coatings produced by HVOF thermal spraying process

In this work, the Fe–Si based thermal sprayed coatings were synthesized using HVOF in order to obtain ferromagnetic materials. Ultra-fine grain Fe–Si based coatings were synthesized by HVOF thermal spraying using nanostructured powders obtained from mechanical milling. Magnetic measurements revealed a soft magnetic character for all the coatings. Additions of boron, niobium and copper which can be regarded as non-magnetic inclusions caused a slight increase of coercivity. In order to investigate the stability of the magnetic properties of thermal spray deposits during their application, relaxation heat treatments was carried out. The result shown the high thermal stability in magnetic properties of the deposits and allow to using these deposits in several magnetic applications even to high temperatures.