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F. Warchomicka, M. Stockinger, H.P. Degischer:
"Flow behaviour and microstructure during hot deformation of Ti-5Al-5Mo-5V-3Cr-1Zr";
Poster: 11 th World Conference on Titanium, Kyoto/ Japan; 06-03-2007 - 06-07-2007; in: "Proceedings of Ti-2007, The 11th World Conference on Titanum", (2007), ISBN: 978-4-88903-406-6; 511 - 514.

The near beta titanium alloys are widely used for aerospace applications in structural parts. They also present a better forgeability at lower temperature than the a + b titanium alloys. In this work, a modified version of alloy VT22, Ti-5Al-5Mo-5V-3Cr-1Zr (Ti-5-5-5-3-1), is studied to determine the flow behaviour in the a+b and b field and the effect of the temperature, time, strain and strain rate on the microstructure. Compression tests and heat treatments were performed by means of Gleeble® 1500 machine around b-transus temperature. Compression tests were carried out at 0.01, 0.1 and 1s-1 of constant strain rate. In the a+b field, the flow curves show a continuous softening at 0.1 and 1s-1 and steady flow at 0.01s-1 of strain rate. Above b-transus temperature, a steady state flow for all the strain rates is observed. The evolution of the globular a phase and the b sub-grains before and after the deformation are examined by quantitative analysis of SEM images to identify the deformation mechanisms dominating during hot working.

Near beta titanium alloys; Ti-5-5-5-3-1; Hot deformation; Flow Curves; Microstructure