Fabricating TiC particles reinforced Fe-based composite coatings produced by GTAW multi-layers melting process

The present study aims to analyze microstructure and properties of TiC particles reinforced Fe-based surface composite coatings produced by gas tungsten arc welding (GTAW) multi-layers melting process. The mixture powder of graphite and ferrotitanium (FeTi) was deposited evenly on an AISI 1045 steel substrate, which was then heated by GTAW heat source. The results showed that in situ synthesized TiC particle reinforced composite coatings can be achieved under suitable welding parameters. Cubic TiC carbides and fine needle-shape eutectic TiC carbides are formed by ternary eutectic reaction between FeTi and graphite powders. Together with these TiC carbides, radially grown dendrites of primary TiC particles are also found in the composite coatings. These TiC particles are evenly distributed in the composite coatings. Because of the generation of these carbide particles and their homogeneous distribution in the matrix, the composite coatings give very high hardness and excellent wear resistance. The wear resistance of multi-layers composite coatings is about three to four times higher than that of 1045 steel substrate. Moreover, the wear resistance of the composite coatings and the substrate increased with increasing wear sliding distance.