Nanostructure of immiscible Mg–Fe dissimilar weld without interfacial intermetallic transition layer

The immiscible pure Mg–Fe dissimilar materials were welded without interfacial intermetallic transition layer, which is normally necessary to the immiscible couple with arbitrary large lattice mismatch. The nanostructure of the weld interface demonstrates a new mechanism of dissimilar welding: a Mg nano grain layer at the weld interface bonded bulk Mg and Fe grains. The Mg nano grain layer formation and its role on welding are discussed. Meanwhile, Mg–Fe dissimilar weld with interfacial intermetallic transition layer was studied. The nanostructure of the two types of weld with and without intermetallic layer is compared.