Fabrication of bulk nanocrystalline Fe–Ni alloys with high strength and high ductility by an electrodeposition

●Bulk nanocrystalline Fe–Ni alloys with 43–56 wt% nickel were electrodeposited.●Microstructures and tensile properties of electrodeposits were investigated.●Bulk nanocrystalline Fe–Ni alloys exhibited high strength and high ductility.●Size of dimples is 10 times the grain size in electrodeposits with high ductility.

The tensile behavior of electrodeposited bulk nanocrystalline Fe–Ni alloys with a grain size of approximately 15 nm was investigated. Electrodeposited alloys with a nickel content of 43–56 wt% have a single-phase face-centered cubic structure. These alloys exhibited a good combination of tensile strength and ductility in tensile tests at room temperature. In particular, bulk nanocrystalline Fe–44 wt% Ni exhibited the high tensile ductility of 1.7 GPa and significant ductility of 16%, and the tensile specimen after fracture showed clear necking. Fracture surface observation indicated that dimples, the size of which was 10 times the grain size, developed in electrodeposits with high ductility of above 10%. The results of this study point out that grain clusters can have a role in plastic deformation during tensile loading.