Continuous Dynamic Recrystallization in Dual-Phase Titanium Alloy in Superplasticity

Abstract:

A new class of superplastic titanium alloy, Ti–4.5Al–2.5Cr–1.2Fe–0.1C–0.3Cu–0.3Ni, was deformed at 1073 K with strain rates of 1×10⁻⁴–1×10⁻¹ s⁻¹, and microstructures in the condition between superplastic regions II and III (= 1×10⁻² s⁻¹) were observed using scanning electron microscope and electron back-scattered diffraction. Continuous dynamic recrystallization was observed, resulting in grain refinement both in α and β phases. The grain size decreased significantly in α phase at the early stage of the deformation and in β phase at the later stage. In the recrystallized microstructure, the major sub-boundaries formed perpendicularly to slip directions <11−20> in α phase and parallel to slip planes {110} in β phase, which might be caused by the difference in the symmetry of the crystal structures.

• Periodical: Defect and Diffusion Forum (Volume 385)
• Pages: 126-130
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.385.126
• Online since: July 2018
• Authors: Keita Sekiguchi*, Hiroshi Masuda, Hirobumi Tobe, Eiichi Sato
• Keywords: Continuous Dynamic Recrystallization, Dislocation, Rapid Plastic Forming, Titanium Alloy

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