Effects of molybdenum, titanium and silicon additions on the Do \u3c inf\u3e 3 ⇄ B2 transition temperature for alloys near Fe \u3c inf\u3e 3 Al

Additions of molybdenum, silicon and titanium to FeAl alloys with an aluminium content in the range 20-28 at.% have been found to increase the D03 ⇄ B2 transition temperature Tc by as much as 250°C over that for binary FeAl alloys (Tc ≈ 540°C). These increases in Tc have been related to increases in the ordering energies of the DO3 superlattice caused by specific site substitutions by the solutes. The study of a variety of alloys, both ternary and higher order, has permitted development of an empirical expression relating Tc to the amounts of moly b-denum and titanium as well as to the aluminum content. The effectiveness of the solutes in raising Tc decreases in the order silicon, titanium and molybdenum. © 1987