Mechanism of saturated flow stress during hot tensile deformation of a TA15 Ti alloy

The flow stress of a TA15 Ti alloy saturates after a true strain of 10% deformed at 750 °C whilst the dislocation density is not saturated and increases continuously with straining as illustrated by the geometrically necessary dislocation (GND) density maps. The GND densities for strains of 0%, 10%, 20%, and 30% are shown in (a), (b), (c) and (d), respectively. The present work demonstrates that the saturation of flow stress is not due to the saturation of dislocation density, which is different to the common steady state deformation.523