Preparation of high performance Ti–6Al–4V alloy thin strip by on-line warm rolling and study of its microstructure evolution and mechanical properties

Abstract

To address the challenges associated with preparing thin strips of difficult-to-deform materials – such as low processing efficiency and yield, poor shape, and subpar performance – our research team developed an on-line warm rolling experimental machine featuring hydraulic tension. We used the Ti–6Al–4V alloy as our experimental material and conducted warm rolling experiments at various temperatures, thoroughly examining the intricate relationship between microstructure evolution and mechanical properties. Our findings indicate that warm rolling causes a clear refinement of the α phase and β phase microstructures, while intensifying dislocation entanglement. These changes significantly enhance the strength of the Ti–6Al–4V alloy, though Total Elongation Limit (TEL) decreases. After evaluating mechanical properties, surface quality, and energy consumption associated with warm rolling, we determined the optimal warm rolling temperature for the Ti–6Al–4V alloy to be 650 °C. At this temperature, the Ultimate Tensile Strength (UTS), Yield Strength (YS), and TEL were 1325 MPa, 1164 MPa, and 8.0%, respectively, maintaining good ductility. The impressive performance of the Ti–6Al–4V alloy sheet is mainly attributed to the strengthening effects of fine grain and dislocation, while the introduction of some fine recrystallization enhances ductility. High-performance Ti–6Al–4V alloy thin strip was successfully prepared by on-line warm rolling with hydraulic tension, which provided a new idea for the preparation of thin strip of difficult-to-deform materials.

Keywords

• Ti–6Al–4V alloy
• Hydraulic tension
• On-line warm rolling
• Microstructure evolution
• Mechanical property
• Dynamic recrystallization