Reactive casting of Ni-Al-Fe ternary intermetallic alloys

NiAl-base intermetallic alloys containing iron up to 25 at % are produced b y reactive casting, which involves an exothermic reaction between elemental liquids and enables one to cast high-melting-point intermetallic allays wi thout the need of external heating. In this study, aluminum liquid at 1 023 K and a molten nickel-iron alloy at 1 773 K are mixed to produce a molten Ni-Al-Fe ternary intermetallic alloy with a temperature of over 2 300 K, wh ich is approximately 400 K higher than the melting point of the alloy produ ced. The concentrations of the constituent elements are approximately homog eneous in the ingot of 30 mm in diameter and 130 mm in height. The grain si ze of the ingot decreases, as the iron content increases. The increase in i ron content improves the hardness, bending strength and wear resistance of the alloy. Young's modulus of the alloy decreases with the increase in temp erature and iron content.