• Connolley, T.
• Swygenhoven, H. Van
• Petegem, S. Van
• Šmíd, M.
• Sofinowski, K.
• Rahimi, Salah

Abstract

Plastic effects during sheet metal forming can lead to undesirable distortions in formed components. Here, the three-stage work hardening and plastic strain recovery ("springback") in a cold-rolled, α-phase commercially pure titanium is examined. Interrupted standard tensile tests with in situ x-ray diffraction and quasi-in situ electron backscatter diffraction show that twinning plays a minor role in both of these phenomena. The experiments give evidence that the observed work hardening plateau is the result of an abrupt activation and multiplication of 〈c+a〉 slip and a subsequent redistribution of load between grain families. The springback can be attributed to inelastic backwards motion and annihilation of dislocations, driven by backstresses from dislocation-based hardening during loading. The peak broadening behavior, observed by x-ray diffraction, suggests that the internal stress state is highest in the rolling direction, resulting in consistently higher springback magnitude along this direction.

Topics

• impedance spectroscopy
• polymer
• grain
• phase
• x-ray diffraction
• experiment
• dislocation
• titanium
• forming
• activation
• electron backscatter diffraction
• commercially pure titanium