Thermodynamic assessment of the Ni–Te system

Carl-Magnus Arvhult (1) , Christine Gueneau (2, 3) , Stéphane Gossé (3, 2) , Malin Selleby (1)

1 MSE - Department of Materials Science and Engineering [Stockholm]
2 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
3 SCCME - Service de la Corrosion et du Comportement des Matériaux dans leur Environnement

A thermodynamic assessment of the Ni–Te system has been performed using the Calphad method, based on experimental data available in the literature. The proposed description has been developed for use in the modeling of fissionproduct-induced internal corr sion of stainless steel cladding in Generation IV nuclear reactors. DFT calculations were performed to obtain 0 K properties of solid phases to assist the thermodynamic optimization. The ionic liquid two sublattice model was used, and most solution phases were modeled using interstitial metal sub-lattices. With a strict number of parameters, the resulting description satisfactorily reproduces all thermodynamic properties and hightemperature phase transitions. The metastable miscibility gap in the Ni-rich liquid that is experimentally suggested is not present in the final description. The $\delta$ phase exhibits a metastable order-disorder transition between the CdI$_2$ and NiAs types of interstitial nickel distribution. The CdI$_2$ prototype is the stable space group at room temperature. Low-temperature ordering phase transitions have been disregarded in this description, since they are not of interest to the application of corrosion in nuclear reactors.

Domaines: Chimie

Carl-Magnus Arvhult, Christine Gueneau, Stéphane Gossé, Malin Selleby. Thermodynamic assessment of the Ni–Te system. Journal of Materials Science, 2019, 54 (16), pp.11304-11319. ⟨10.1007/s10853-019-03689-0⟩. ⟨hal-03160221⟩