Volume 2, Issue 5 (May 2005)
Microstructure and Phase Control in Zr-Fe-Cr-Ni Alloys: Thermodynamic and Kinetic Aspects
TEM investigations in Zr-Fe and Zr-Fe-Ni, Zr-Ni-Cr and Zr-Cr-Fe systems were performed to assess the second particles present in these alloys, either in quasi equilibrium conditions, or after quenching and annealing experiments.
At equilibrium, Zr3Fe was found to dissolve Ni up to 12 at%. Ab initio computations provided formation enthalpies for several Zr-Fe compounds and showed that the Zr2Fe is metastable at low temperature. All of these data allowed us to extend the thermodynamic database ZIRCOBASE; very good agreement between the thermodynamic computations and the experimental evidences was obtained.
Quenching and annealing experiments showed that Zr2Fe is formed for low quenching rates, while Zr3Fe is formed for higher quenching rates.
Last, corrosion results in various conditions show that the influence of second phase particles volume fraction depends on the corroding atmosphere.