Mechanical Properties of Ti–6Al–4V Titanium Alloy with Submicrocrystalline Structure Produced by Severe Plastic Deformation

Abstract

A comparative investigation of mechanical properties of Ti–6Al–4V titanium alloy with microcrystalline and submicrocrystalline structures in the temperature range of 20–600°C has been carried out. The grain sizes under the submicrocrystalline and microcrystalline conditions are 0.4 and 10 μm, respectively. The alloy with the microcrystalline structure has been additionally subjected to a heat-strengthened treatment. The structure refinement of the alloy results in increase in both strength and fatigue limit at room temperature by about 20%. With increasing deformation temperature, the strength of the submicrocrystalline alloy is higher than that of the microcrystalline alloy up to 400°C. However, the creep strength of the submicrocrystalline alloy is slightly lower than that of the heat-strengthened microcrystalline alloy already at 250°C.