Dynamic Spheroidization Mechanism and Its Orientation Dependence of Ti-6Al-2Mo-2V-1Fe Alloy during Subtransus Hot Deformation

The dynamic spheroidization mechanism and its orientation dependence in Ti-6Al-2Mo-2V-1Fe alloys during subtransus hot deformation were studied this work. For purpose, compression tests carried out at temperatures of 780–880 °C, with strain rates 0.001–0.1 s−1. Based on SEM, EBSD TEM characterization, the results showed that aspect ratio α phase decreased increasing decreasing rates. At 880 °C/0.001 s−1, was smallest 2.05. proportion HAGBs rates, which different from trend spheroidization; indicated formation not necessary for process. Furthermore, α/α interface related to evolution dislocations twin boundaries high (880 °C) low (780 °C), respectively. Moreover, lamellar crystallographic tilt direction (θ) clarified: when θ between 45° 60°, both prism <a> slip basal systems activated together, more favorable spheroidization. This study could provide guidance titanium alloy process designs microstructure regulation.