Description
Successful hot forming of titanium alloys requires the selection of appropriate forming conditions to achieve the desired final microstructure. This investigation focuses on the evolution of the substructure of a Ti-17 alloy during hot deformation. Hot compression experiments are carried out at constant and stepped strain rates between 0.001 s-1 and 0.1 s-1 below the β-transus temperature. The mechanical and microstructural responses during hot deformation are compared between two conditions: a) α and β phases in quasi-equilibrium state and b) pure β-metastable quenched microstructure in the α+β domain. During deformation of the metastable β-phase an increase in the aspect ratio of prior β-grains and formation of substructure in regions close to the prior β-grain boundaries are observed. In contrast, when α and β phases coexist in equilibrium, a network of low and high-angle grain boundaries homogeneously distributed within the prior β-grains is produced during deformation. A rapid change in strain rate during plastic deformation shows that the final substructure depends on the thermomechanical history only if high amount of dislocations is produced in the first step of deformation. Furthermore, the microstructure and, consequently, the stresses need time to adapt to the new strain rate.| Period | 15 Jun 2023 |
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| Held at | The Institute of Materials, Minerals and Mining, United Kingdom |
| Degree of Recognition | International |