Hot deformation behavior and globularization mechanism of Ti-6Al-4V-0.1B alloy with lamellar microstructure

• Published in: Rare metals 2013-04, Vol.32 (2), p.122-128
• Main Authors: Yu, Yang, Xiong, Bai-Qing, Hui, Song-Xiao, Ye, Wen-Jun
• Format: Article
• Language: English
• Subjects: Biomaterials; Chemistry and Materials Science; Deformation; Dynamic recrystallization; Energy; Materials Engineering; Materials Science; Metallic Materials; Microstructure; Migration; Nanoscale Science and Technology; Physical Chemistry; Recrystallization; Softening; Strain rate; Titanium base alloys
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-013-0022-4

Hot deformation behavior and globularization mechanism of Ti-6Al-4V-0.1B alloy with lamellar microstructure were quantitatively studied through isothermal compression tests with the temperature range of 850–950 °C and strain rate range of 0.01–1.00 s −1 . The results show that the peak flow stress and steady stress are sensitive to the strain rate and temperature. The value of deformation activation energy is 890.49 kJ·mol −1 in (α + β) region. Dynamic recrystallization is the major deformation mechanism. Flow softening is dominated by dynamic recrystallization at 850–950 °C. TiB particles promote the recrystallization of α laths. Globularization processes consist of four steps: formation of subgrain after dynamic recovery in α plates; subgrain boundary migration caused by α/β interfacial instability; interfacial migration promoting β phase wedge into α phase; disintegrating of α laths by diffusion processes; and grain-boundary sliding. Globularization mechanisms during hot deformation processes of the Ti-6Al-4V-0.1B alloy with lamellar structure are continuous dynamic recrystallization.