An overview on the microstructure and properties of Fe/Ti based dissimilar joints

Joining of Ti and Fe-based alloys is challenging due to the formation of deleterious phases at the interface. Since fusion welding is unsuitable for the purpose, over the years, many solid-state welding techniques have been tried. This review provides a comparison of different solid-state joining methods used for Fe/Ti alloys with focus on the structural transformations in base materials, effect of process parameters on interface microstructure, its evolution and kinetics with thermal aging and structure-property correlation. Structural transformations in diffusion couples (near-equilibrium condition) are compared with those in weldments and a perspective is provided on the role of defects and alloying additions in enhancing/retarding reaction zone formation under both equilibrium and non-equilibrium conditions.