Generation of high-performance Ni-Cr-Mo-based superalloys via γ to DO22 superlattice ordered phase transformation upon addition of trace alloying elements

The mechanical properties of Ni-Cr-Mo-based alloys with tailored ordered phases were investigated. Introduction of niobium induced the formation of a DO22 superlattice and stabilized this structure by avoiding its precipitation in ternary Ni-Cr-Mo. The tetragonal structure and high thermal stability of DO22 resulted in alloys with higher hardness (13 GPa) and the Young′s modulus (225 GPa). Moreover, the sample containing the DO22 phase showed low creep strains and creep strain rates at holding time.