Embodiments of the present disclosure relate to nickel-base alloys and methods of direct aging nickel-base alloys. More specifically, certain embodiments of the present disclosure relate to methods of direct aging 718Plus.RTM. nickel-base alloy to impart improved mechanical properties, such as, but not limited to, tensile strength, yield strength, low cycle fatigue, fatigue crack growth, and creep and rupture life to the alloys. Other embodiments of the present disclosure relate to direct aged 718Plus.RTM. nickel-base alloy, and articles of manufacture made therefrom, having improved mechanical properties, such as, but not limited to, tensile strength, yield strength, low cycle fatigue, fatigue crack growth, and creep and rupture life.