Effect of slagging flux on Fe-Al intermetallic coatings synthesized by laser cladding

The iron-aluminide intermetallic coatings were in-situ synthesized on Q235 steel by laser cladding. The cladding powders were mixed iron and aluminum powders with or without slagging flux. The effects of slagging flux on the microstructure and properties of the cladding coatings were studied. The results indicate that adding slagging flux into the cladding powders not only refines the grains of the cladding layers, but also has a significant influence on the properties of the iron-aluminide coatings. The XRD results show that the main phases of the iron-aluminide coatings both are FeAl with B2 phase structure and Fe₃Al with DO3 phase structure, but the ratio of Fe₃Al increases as slagging flux was added. In addition, the iron-aluminide cladding layers with slagging flux shows higher microhardness, better oxidation resistance and better corrosion resistance than those free of slagging flux.