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alloy has a yield strength near 1,950 MPa, and a tensile strength near 2,200 MPa, with total elongation of 8.2% and a uniform elongation of 3.8%. The combination of strength and ductility is competitive with the best reported for both maraging and secondary hardening steels (Fig. 1). Finally, the results presented by Lu and colleagues document that Ni(Fe,Al) can be a very effective hardening precipitate, leading to UHSSs that are also economically attractive since they avoid expensive species such as Co and Ti. But there are a number of other issues that must be addressed before these alloys become viable candidates for important structural applications. An important example is the fracture toughness of the alloy, which is not reported. There is reason for concern, since alloys strengthened by NiAl precipitates, such as PH 13–8, are susceptible to cleavage fracture at ambient temperature12 and lose toughness rapidly with strength7. However, brittle cleavage fracture is not overcome metallurgically by changing the precipitate distribution, but rather by modifying the underlying martensitic microstructure, as is done effectively, for example, in the AerMet 100 alloy13. A similar approach could be useful in the 18–3 alloy discussed here. ❐