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Nickel-based superalloys are used in load-bearing structures requiring the highest homologous temperature of any common alloy system (Tm = 0.9, or 90% of their melting point). Among the most demanding applications for a structural material are those in the hot sections of turbine engines (e.g. turbine blade). They comprise over 50% of the ...
Directional solidification is the preferred technique for casting high temperature nickel-based superalloys that are used in turbine engines of aircraft. Some microstructural problems such as coarse dendritic structure, long dendrite side branches, and porosity hinder the full potential of single crystal ni-based alloys. [6]
In nickel-based superalloys, regions of Ni 3 Al (called γ' phase) precipitate out of the nickel-rich matrix (called γ phase) to give high strength and creep resistance. Many alloy formulations are available and they usually include other elements, such as chromium, molybdenum, and iron, in order to improve various properties.
Therefore, the precise control of grain size in nickel-based superalloys is key to creep resistance and mechanical reliability and longevity. Some ways to control the grain size lie in the manufacturing techniques like directional solidification and single crystal casting. [12]
Modern turbine blades often use nickel-based superalloys that incorporate chromium, cobalt, and rhenium. [14] [18] Aside from alloy improvements, a major breakthrough was the development of directional solidification (DS) and single crystal (SC) production methods.
Inconel Alloy 625 (UNS designation N06625) is a nickel-based superalloy that possesses high strength properties and resistance to elevated temperatures. It also demonstrates remarkable protection against corrosion and oxidation.
Alloys of nickel are the most common but includes iron aluminum alloys. [1] Applications include high temperature turbine blades and heat exchanger tubing, [2] while steels are used in nuclear applications. [3] ODS materials are used on spacecraft to protect the vehicle, especially during re-entry. Noble metal ODS alloys, for example, platinum ...
Investment casting is an industrial process based on ... process are the high nickel-based alloy and super alloys. ... can include single-crystal (SX), directionally ...