Abstract
Abstract Time-dependent springback of a commercially pure titanium sheet was investigated experimentally from the viewpoints of strain rate, holding time at the bottom dead center before unloading, and elapsed time after unloading. A draw-bending test showed that the amount of springback decreased linearly with the holding time before unloading when plotted on logarithmic scale and increased with the elapsed time after unloading. To investigate the mechanism of these results, stress relaxation and creep tests were conducted. The variation of the amount of springback with the holding time corresponded well with that of the stress during stress relaxation. On the other hand, the in-plane anisotropy in the evolution of the amount of springback with the elapsed time did not correspond with that of creep strain. The mechanism of the in-plane anisotropy in the elapsed-time dependency was discussed in terms of the stress relaxation and creep behaviors.
Highlights
Pure titanium (CP-Ti) sheets are distinguished in their high specific strength and corrosion resistance, and are generally using forming in is regarded of the Commercially pure titaniummanufactured (CP-Ti) sheets are press distinguished theirSpringback high specific strength as andone corrosion significant defects sheet forming
Because the critical resolved shear stress (CRSS) is different depending on the slip system in CP-Ti [3], it is hypothesized that a similar microscopic deformation occurred during stress relaxation a sheet is not completely unloaded during stress relaxation
Stress relaxation and creep tests were conducted to understand the mechanism of time-dependent springback
Summary
Pure titanium (CP-Ti) sheets are distinguished in their high specific strength and corrosion resistance, and are generally using forming in [1,2,3]. The elapsed time-dependent springback was investigated in aluminum alloy and high strength steel sheets respectively by Wang et al [6] and Lim et al [7] In their works anelasticity and creep driven by residual stress were focused on as the mechanism of the elapsed time-dependent springback. Because CP-Ti sheets exhibit high strain-rate sensitivity and large stress relaxation and creep behaviors at room temperature [8,9,10], time-dependent springback would be pronounced. A draw-bending test was performed at room temperature to examine time-dependent springback of the sheet from the viewpoints of strain rate, holding time at the bottom dead center before unloading, and elapsed time after unloading. Stress relaxation and creep tests were conducted to understand the mechanism of the time-dependent springback of the CP-Ti sheet
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
