PHASE-TRANSFORMATION IN PU-GA ALLOYS AT LOW-TEMPERATURE AND UNDER PRESSURE - LIMIT STABILITY OF THE DELTA-PHASE

The mechanisms and morphologies obtained during partial transformation delta-(PuGa)-->alpha' at low temperature and under uniaxial or isosta tic pressure have been determined. Depending on the conditions of trea tment, one can observe two different phenomena: i) diffusion and marte nsitic transformations occur simultaneously and alpha' phase morpholog y is plate shaped, ii) only martensitic transformation occurs and alph a' phase morphology is lenticular. (C) 1998 Published by Elsevier Scie nce S.A.