Factors contributing to the strength of a polycrystalline nickel–cobalt base superalloy

The strengthening behaviors of a new polycrystalline Ni–Co base superalloy are analyzed by measuring its Vickers hardness over a range of structural scales, from nano to micro. The results clearly show, for the first time, the contributions of boundaries (grain, annealing twin and primary γ′) and secondary and tertiary γ′ precipitates in solid solutions to the total strength of such polycrystalline superalloys.