Abstract
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In the present study, two powders near-b Ti
alloys having a nominal composition of Ti-5Al-5Mo-5VXCr-
1Fe (X = 1–2, wt%) were studied. The alloys were
produced via the blended elemental powder metallurgy
technique using hydrogenated Ti powder. Microstructure
evolution and the distribution of the alloying elements
between the phases were investigated after each step of
thermo-mechanical processing (TMP). Microstructures
were refined through the TMP in both alloys. Porosity was
reduced with deformation at 1173 K (900 C) in the b
phase field. The b ? a phase transformation occurred
during soaking at 1023 K (750 C) in the a ? b phase
field. Fragmentation of the continuous grain boundary a
occurred because of the 40 % deformation at 1023 K
(750 C). Variation in the concentration of the alloying
elements in each phase took place through the diffusion
during soaking in the a ? b phase field, e.g. exit of
b-stabilisers from the a-phase. However, the a phase
remained supersaturated with b stabilisers. Deformation
had no influence on the distribution of the alloying elements.
An addition of 1 % Cr content slightly affects the
amount of the a phase formed and b grain size, but it has no
noticeable effect on the distribution of the alloying elements
between the phases.