The effect of environment and strain rate on the room temperature tensile properties of FeAl single crystals

Specimens from three FeAl single crystals, with compositions of Fe–40Al, Fe–40Al–1Y and Fe–43Al, were strained at room temperature at strain rates from 1×10−6 to 1 s−1 in air and vacuum. In air, both the elongation to fracture and fracture strength increased rapidly with increasing strain rate up to 1 s−1, whereas strain rate had no effect upon tests performed in vacuum. The yield strength increased with increasing strain rate up to 1×10−2 s−1 in air, but was strain-rate independent in vacuum. Prestraining by 5% under compression, either reduced or had no effect on the subsequent tensile ductility. Transgranular cleavage fracture occurred in all specimens.