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Byline: Zhubin He, Bugang Teng, Shijian Yuan, Z.R. Wang In bending with PUR pad, profile with different curvature radius can be manufactured. Experiment of trough-shaped profile was carried out to investigate the effect of section shape, penetration depth, roller radius and PUR pad thickness. Results show that both the position of neutral surface and section moment of bending have significant effect on curvature radius. Profile with bigger section moment of bending is difficult to bend. Curvature radius of bent profile decrease sharply when penetration depth increase. Change of roller radius has similar effect as the position of neutral surface. PUR pad thickness has big effect under small penetration depth.

The precise characterisation of hot flow behavior of titanium alloys is of vital importance for practical hot forming processes. To precisely determine the hot flow behavior of titanium alloys under the forming conditions, Gleeble hot tensile tests are usually performed to simulate the forming processes by accurately controlling the deformation temperatures and strain rates under designed conditions. However, there exists a non-uniform temperature distribution during the Gleeble tests, which leads to inaccuracies in the determined hot flow behavior. To overcome such an issue, this paper proposed a new strain-based correction method for Gleeble hot tensile tests, enabling the mitigation of the non-uniform temperature-induced stress-strain curve inaccuracies. The non-uniform temperature zones have been successfully excluded in the calculation of the true strain levels. A series of hot uniaxial tensile tests of TA32 at temperatures, ranging from 750 °C to 900 °C, and strain rates, 0.01/s~1/s, were carried out. The obtained stress-strain correlations for a large gauge zone were characterized using the new correction method, which was further used to evaluate the hardening behavior of titanium alloys. The results have shown that the ductility, strain hardening component (i.e., n), strain rate hardening component (i.e., m) and uniform strain value (i.e., ε u ) are over-estimated, compared to conventional method. Higher strain rates and lower temperature leads to enhanced hardening behavior. This research provides an alternative correction method and may achieve more accurate stress-strain curves for better guidance of the hot forming process for titanium alloys. [ABSTRACT FROM AUTHOR]