Study of the microstructural evolution of α-quenched or cold-rolled zirconium alloys during isothermal agings between 20 and 400 C

The thermoelectric power (TEP) at 20 C of cold rolled or quenched zirconium alloys has been measured as a function of aging time at temperatures between 20 and 400 C. Two stages of TEP evolution are observed in cold-rolled specimens and are attributed respectively to the migration of oxygen atoms towards dislocations, and to the formation of oxygen clusters on dislocation nodes, the diffusion of oxygen atoms being enhanced by vacancies due either to cold rolling or to quench. Only the first stage is observed in specimens quenched from the upper limit of the α-domain, due to the low density of quench dislocations. (orig.)