We show that a bulk nanostructured material combining high strength, high ductility, and high thermal stability can be synthesized in a Ni-Mo-Nb alloy with composition approaching Ni3(Mo, Nb). By means of a simple aging treatment at700°C, the grains of the parent face-centered cubic phase are made to transform into nanosized ordered crystals with DO22superlattice maintaining a size of 10–20 nm after up to 100 hours of aging and corresponding room-temperature yield strength of 820 MPa and tensile ductility of 35%. Deformation of the superlattice is found to predominantly occur by twinning on{111}planes of the parent phase. It is concluded that, although the respective slip systems are suppressed, most of the twinning systems are preserved in the DO22superlattice enhancing the ductility.
Core-shell structured titanium-nitrogen alloys with high strength, high thermal stability and good plasticity
