Nickel aluminide

Nickel aluminide refers to either of two widely used intermetallic compounds, Ni₃Al or NiAl, but the term is sometimes used to refer to any nickel–aluminium alloy. These alloys are widely used because of their high strength even at high temperature, low density, corrosion resistance, and ease of production.^[1] Ni₃Al is of specific interest as a precipitate in nickel-based superalloys, where it is called the γ' (gamma prime) phase. It gives these alloys high strength and creep resistance up to 0.7–0.8 of its melting temperature.^[1][2] Meanwhile, NiAl displays excellent properties such as lower density and higher melting temperature than those of Ni₃Al, and good thermal conductivity and oxidation resistance.^[2] These properties make it attractive for special high-temperature applications like coatings on blades in gas turbines and jet engines. However, both these alloys have the disadvantage of being quite brittle at room temperature, with Ni₃Al remaining brittle at high temperatures as well.^[1] To address this problem, has been shown that Ni₃Al can be made ductile when manufactured in single-crystal form rather than in polycrystalline form.^[3]