Superplastic Behavior and Microstructural Features of the VT6 Titanium Alloy with an Ultrafine-Grained Structure during Upsetting.

In this paper, the superplastic behavior of the two-phase titanium alloy VT6 with an ultrafine-grained (UFG) structure produced by equal-channel angular pressing is examined. The deformation of specimens with a UFG structure was performed by upsetting in a temperature range of 650-750 °C and strain rate range of 1 × 10-5 × 10 s. Under these conditions, an increased strain-rate sensitivity coefficient m was observed.

Effect of the Texture of the Ultrafine-Grained Ti-6Al-4V Titanium Alloy on Impact Toughness.

In this work, the strength properties and impact toughness of the ultrafine-grained (UFG) Ti-6Al-4V titanium alloy produced by severe plastic deformation (SPD) in combination with upsetting were studied, depending on the direction of crack propagation. In the billets processed by equal-channel angular pressing (ECAP), the presence of anisotropy of ultimate tensile strength (UTS) and ductility was observed, conditioned by the formation of a metallographic and crystallographic texture. At the same time, the ECAP-processed UFG alloy exhibited satisfactory values of impact toughness, ~0.