Prediction of Secondary Phases

The TCS Zr-based Alloys Database (TCZR) can be used to calculate phase equilibria, including phase fractions and compositions, where it reliably accounts for phase transformations with light impurities (O, H, etc.).

All the stable solution phases and intermetallic compounds included with the database are assessed along with the extrapolated systems. The database is able to predict the formation of secondary phases for a given composition within the recommended composition range of the database.

Harte et al. [2018Har] reviewed the secondary phases formed in the Zr-Nb-Fe-Sn-O materials. In the plot below, the results are summarized and applied to an isothermal section of the Zr-Nb-Fe at 973 K. It reveals the type and compositional distributions of the secondary phases, although in some cases the experimental data are quite scattered.

Calculated Zr-Nb-Fe isothermal section at 973 K with second-phase compositions in the Zr-Nb-Fe-Sn-O alloys

Figure 1: Calculated Zr-Nb-Fe isothermal section at 973 K with second-phase compositions in the Zr-Nb-Fe-Sn-O alloys reviewed by Harte et al. [2018Har].

Reference

[2018Har] A. Harte, M. Griffiths, M. Preuss, The characterisation of second phases in the Zr-Nb and Zr-Nb-Sn-Fe alloys: A critical review. J. Nucl. Mater. 505, 227–239 (2018).