The dynamic responses of lamellar and equiaxed near β-Ti alloys subjected to multi-pass cross rolling. (15th April 2020)

• Record Type: Journal Article
• Authors: Chen, Wei; Wang, Hande; Lin, Y.C.; Zhang, Xiaoyong; Chen, Chao; Lv, Yaping; Zhou, Kechao
• Is Part Of: Journal of materials science & technology. Volume 43(2020)
• Page Start: 220
• Page End: 229
• Publication Date: 2020-04-15
• Subjects: Near β-Ti alloys -- Multi-pass cross rolling -- Dynamic recrystallization -- 11¯01 Twinning -- β-twinning; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2019.10.017
• Languages: English
• ISSNs: 1005-0302

Abstract

Abstract: This work gives a comparison on the microstructural characteristics, textural discrepancies, and twinning behaviors of lamellar and equiaxed near β-Ti alloys during multi-pass cross rolling with a rolling reduction of 20 %, 50 % and 80 %. The results showed that the restoration mechanism of the alloy in β phase is strongly dependent on the α morphologies, and in comparison, strain path has weaker influences on the grain refinement of the β matrix. Therefore, the texture intensities of both α and β phases were weakened owing to the dynamic recrystallization (DRX) of the two phases in the equiaxed microstructure. While, with regard to the lamellar microstructure, dynamic recovery (DRV) of the β phase predominated, forming elongated β subgrains. Besides, the α and β matrix in lamellar microstructures obeyed the Burgers orientation relationship, which was gradually broken down until the final reduction. Lastly, the 1 1 ¯ 01 twinning exhibits a strong size effect. With the continuous DRX of α phases, the α-twinning is suppressed owing to progressive grain refinement. The activation of β-twinning, namely 332 〈 113 〉 and 112 〈 111 〉, in near β-Ti alloys is heavily dependent on the deficient β-stabilizing elements and the local stress concentration. These findings provide an effective way to obtain ultra-fine grain microstructures of this alloy.