Reactive casting of B2-ordered Ni-Al-Co ternary intermetallic alloys

Extremely superheated liquid of high-melting-point NiAl-base intermetallic alloys have been produced and cast into a cylindrical bar using the reactiv e casting method, which is based on the exothermic self-propagating high-te mperature synthesis (SHS) reaction between elemental liquids. When liquid a luminum of 1023 K and a molten nickel-cobalt alloy of 1773 K are mixed, the y exothermically react and produce a cobalt-containing NiAl liquid with a t emperature over 2300 K, The liquid solidifies into a B2-ordered beta -phase intermetallic alloy. When the cobalt concentration of the alloy increases, the density, hardness, wear resistance, coefficient of thermal expansion a nd corrosion resistance to hydrochloric acid increase, while the thermal co nductivity decreases. The effect of cobalt concentration on the oxidation r esistance of the alloy to hot air is negligible.