Microstructure and properties of arc sprayed coatings containing Fe based amorphous phase and nanocrystallites

An Fe based cored wire was used to deposit wear resistant coatings containing Fe based amorphous phase and nanocrystallites on Q235 steel substrate by arc spraying. The microstructure of the coatings was investigated by scanning electron microscopy and transmission electron microscopy. Electron probe microanalyser and X-ray diffraction analysis were used to study the chemical compositions and phase compositions in the coatings. The microhardness of the coating was determined. The wear behaviour of the coatings was evaluated. The results showed that the coatings contained Fe based amorphous phase and other crystallites such as Fe₂B, Cr₂B, M₂₃(C,B)₆, Fe₃O₄ and α-(Fe,Cr). Some of the crystallites show grain sizes of <30 nm. The coatings were hard. Compared with the reference sample of commercial 3Cr13 coating, the coatings showed a much higher wear resistance; the relative wear resistance of the amorphous coating was 8 times higher than that of commercial 3Cr13 coating.