Superplasticity of the Ultrafine-Grained Ti-6Al-4V Alloy with a Metastable α-Single Phase Microstructure

H. Matsumoto , Vincent Velay (1) , A. Chiba

1 ICA - Institut Clément Ader

This work examines the superplastic flow behavior of the ultrafine‐grained (UFG) Ti‐6Al‐4V alloy (dα = 0.4 μm) (hereafter designed as the α' ‐UFG alloy) consisting of single α phase in relation to microstructural evolution during tensile deformation at 6501, 7001 and 750t. The dynamic β‐precipitation occurs during deformation and contributes to accommodation mechanism of stress concentration at grain boundaries. During superplastic deformation of the α' ‐UFG alloy tested at 700°C, the superplastic deformation mode of grain boundary sliding can be reasonably explained in relation to the Ball‐Hutchison model at initial stage of deformation and the Gifkins Core‐Mantle model at latter stage of deformation.

Domaines: Mécanique des matériaux [physics.class-ph]

H. Matsumoto, Vincent Velay, A. Chiba. Superplasticity of the Ultrafine-Grained Ti-6Al-4V Alloy with a Metastable α-Single Phase Microstructure. TI 2015 - 13th World Conference on Titanium, Aug 2015, San Diego, California, United States. 789-792 (Chapter 133), ⟨10.1002/9781119296126.ch133⟩. ⟨hal-02052460⟩