Abstract: A nanocarbide precipitation strengthened ultrahigh-strength, corrosion resistant, structural steel possesses a combination of strength and corrosion resistance comprising in combination, by weight, about: 0.1 to 0.3% carbon (C), 8 to 17% cobalt (Co), 0 to 10% nickel (Ni), 6 to 12% chromium (Cr), less than 1% silicon (Si), less than 0.5% manganese (Mn), and less than 0.15% copper (Cu), with additives selected from the group comprising about: less than 3% molybdenum (Mo), less than 0.3% niobium (Nb), less than 0.8% vanadium (V), less than 0.2% tantalum (Ta), less than 3% tungsten (W), and combinations thereof, with additional additives selected from the group comprising about: less than 0.2% titanium (Ti), less than 0.2% lanthanum (La) or other rare earth elements, less than 0.15% zirconium (Zr), less than 0.005% boron (B), and combinations thereof, impurities of less than about: 0.02% sulfur (S), 0.012% phosphorus (P), 0.015% oxygen (O) and 0.

Abstract: Aluminum alloys having improved strength at 300° C. characterized by formation from an intermediate amorphous state to a final fcc matrix hardened by optimal 25 nm-diameter Ll2 precipitates with an interphase misfit less than about 4% in all three dimensions and Al23Ni6M4 precipitates where M is one or more elements selected from the group consisting of Y and Yb. An appropriate melt of aluminum with selected transition metals (Co, Cu, Fe, Ni, Ti, Y) and Ll2 stabilizers (Sc, Yb) in amounts of about 2 to 12 and 2 to 15 atomic percent, respectively, is processed to achieve an intermediate amorphous state to dissolve Ll2-forming components. The amorphous alloys are then thermo-mechanically devitrified to a final crystalline microstructure. The alloys have good ductility and a short-term tensile strength exceeding about 275 MPa (40 ksi) at 300° C., and are useful for applications such as high-temperature turbine engine components or aircraft structural components.