Author(s) |
Basak, C.; Keswani, R.; Prasad, G. J.; Kamath, H. S.; Prabhu, N.; Banerjee, S.
|
In most of the binary uranium alloy systems,
different metastable phases can be retained at room temperature
depending on the rate of cooling of the gamma phase. On the
other hand, in U-rich U–Zr system, the gamma phase transforms
into either martensitic a or
Widmanstatten a depending on
the cooling rate. It has not been ascertained so far if any
intermediate phase is involved prior to the martensitic
transformation in U-rich U–Zr system and, therefore, nature of
the intermediate phase remains undetermined. Present
investigation shows the existence of an intermediate phase prior
to the final martensitic transformation. Although the
equilibrium beta phase is known to undergo martensitic
transformation, quenching from the
g phase appears to suppress
the b phase formation. In fact
the present experimental evidence suggests that the most likely
intermediate phase is the monoclinic distortion of alpha phase (aČ),
and not the beta, when gamma phase of U–2 wt%Zr alloy is
quenched rapidly.
|