Nickel-based superalloys are essential materials for high-temperature applications in turbine engines due to their exceptional strength, toughness, and resistance to degradation. These alloys are composed of nickel with various alloying elements, including aluminum, titanium, tantalum, and others, which contribute to their properties. The microstructure of these alloys, particularly the γ' phase, plays a critical role in their strength and performance. The γ' phase forms during solidification and is crucial for strengthening the alloy. Other elements, such as chromium, yttrium, and lanthanum, improve oxidation and corrosion resistance. Minor elements like boron, carbon, and zirconium control grain structure and mechanical properties. However, certain phases, such as topologically closed-packed (TCP) phases, can be detrimental due to their tendency to form and weaken the alloy. Superalloys are processed through various methods, including casting, directional solidification, and wrought processing. Casting produces complex shapes, while directional solidification and wrought processing enhance mechanical properties. The processing routes include vacuum induction melting (VIM), vacuum arc remelting (VAR), and powder metallurgy. Each method has its advantages and challenges, such as avoiding macrosegregation and inclusions. Powder metallurgy is particularly useful for producing high-strength polycrystalline superalloys with fine microstructures. The mechanical properties of superalloys, including tensile strength, creep resistance, fatigue, and cyclic crack growth, are highly dependent on their microstructure. Tensile strength is influenced by the γ' phase and the alloy composition. Creep resistance is enhanced by the presence of the γ' phase, which resists shearing at high temperatures. Fatigue and cyclic crack growth are also affected by the microstructure, with grain boundaries and precipitates playing significant roles. The development of predictive models for these properties is ongoing, as they are complex and depend on multiple factors at different length scales. In summary, nickel-based superalloys are vital for high-temperature applications due to their unique combination of properties. Their microstructure, processing methods, and alloy composition are carefully controlled to achieve the desired performance. Advances in processing and alloy design continue to improve the capabilities of these materials, enabling their use in increasingly demanding environments.Nickel-based superalloys are essential materials for high-temperature applications in turbine engines due to their exceptional strength, toughness, and resistance to degradation. These alloys are composed of nickel with various alloying elements, including aluminum, titanium, tantalum, and others, which contribute to their properties. The microstructure of these alloys, particularly the γ' phase, plays a critical role in their strength and performance. The γ' phase forms during solidification and is crucial for strengthening the alloy. Other elements, such as chromium, yttrium, and lanthanum, improve oxidation and corrosion resistance. Minor elements like boron, carbon, and zirconium control grain structure and mechanical properties. However, certain phases, such as topologically closed-packed (TCP) phases, can be detrimental due to their tendency to form and weaken the alloy. Superalloys are processed through various methods, including casting, directional solidification, and wrought processing. Casting produces complex shapes, while directional solidification and wrought processing enhance mechanical properties. The processing routes include vacuum induction melting (VIM), vacuum arc remelting (VAR), and powder metallurgy. Each method has its advantages and challenges, such as avoiding macrosegregation and inclusions. Powder metallurgy is particularly useful for producing high-strength polycrystalline superalloys with fine microstructures. The mechanical properties of superalloys, including tensile strength, creep resistance, fatigue, and cyclic crack growth, are highly dependent on their microstructure. Tensile strength is influenced by the γ' phase and the alloy composition. Creep resistance is enhanced by the presence of the γ' phase, which resists shearing at high temperatures. Fatigue and cyclic crack growth are also affected by the microstructure, with grain boundaries and precipitates playing significant roles. The development of predictive models for these properties is ongoing, as they are complex and depend on multiple factors at different length scales. In summary, nickel-based superalloys are vital for high-temperature applications due to their unique combination of properties. Their microstructure, processing methods, and alloy composition are carefully controlled to achieve the desired performance. Advances in processing and alloy design continue to improve the capabilities of these materials, enabling their use in increasingly demanding environments.