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 fro m 1x10(-6) to 1 s(-1) in air and vacuum. In air, both the elongation to fra cture and fracture strength increased rapidly with increasing strain rate u p to 1 s(-1), whereas strain rate had no effect upon tests performed in vac uum. The yield strength increased with increasing strain rate up to 1x10(-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 ten sile ductility. Transgranular cleavage fracture occurred in all specimens. (C) 2001 Elsevier Science Ltd. All rights reserved.