ELECTRIC ARC SPRAYING OF INTERMETALIC Fe-Al COATINGS USING DIFFERENT SOLID AND POWDER WIRES

摘要

The mechanism of formation and structure of coatings based on the system iron-aluminum, sprayed by electric arc method using wires of solid cross-section and flux-cored wire were investigated. The grain-size composition, structure and microhardness of particles (spraying products of electrode wires of iron and aluminum) captured from the spraying jet, as well as the structure, phase composition and microhardness of electric arc coatings of the system iron-aluminum were studied. It was found that during spraying of Fe + Al and Fe + AlMg wires, the interaction of particles in the jet does not occur and the products of spraying represent particles of iron and aluminum with the appropriate hardness. In this case, the formation of intermetallics in the coatings also does not occur and they have a heterogeneous structure consisting of the components based on iron and aluminum. It was found that intermetallic FeAl structure is formed only after heat treatment of sprayed coatings at 650°C. During spraying of flux-cored wire PD(Fe-Al) in the process of melting the sheath and the filler, the interphase interaction occurs, which results in the formation of coatings with a microhardness of 2460 ± 290 MPa, the main phase of which is intermetallic Fe_3Al.