Strain rate sensitivity of stress-strain curves in a Ti-Fe-O alloy

The effect of strain rate on stress-strain curves of an α-type Ti-Fe-O alloy was investigated at the strain rate between 2.8×10-5 to 2.7×10-2 s-1 at 293K. Zero strain rate curve, 'Base Curve' was estimated by multiple interrupted crosshead displacement dwell test every 0.02 strain in case of the strain rates of 2.8×10-4 and 2.8×10-5. The relaxation saturated stress-strain points made a single stress-strain curve, 'Base Curve'. Base Curve and stress-strain curves at various strain rates were parallel. This means the stress-strain curves can be separated into strain dependent component and strain-rate dependent component. When Base Curve is fitted with Swift's equation, the stress-strain curves are interpreted as follows, σ=875.5(0.021 + Ε)0.176 + 313.3 (dΕ/dt)0.046, where σ:Stress(MPa), Ε:strain and (dΕ/dt):strain rate.