STATISTICAL THERMODYNAMIC APPROACH TO CARBON SOLUBILITY IN FACE-CENTERED-CUBIC FE1-YNIY ALLOY LATTICE

Carbon solubility in a face centred cubic (fcc) Fe1-yNiy alloy lattice was analysed on the basis of statistical thermodynamics assuming negl igible C-C interaction in the fcc Fe1-yNiy lattice. The minimum carbon solubility was observed for values of y of similar to 0.6-0.7 and app eared to be ascribable to the minimum number of available interstitial sites for occupation by carbon atoms in the fcc Fe1-yNiy lattice arou nd this composition. Accordingly, the extent of stabilisation for carb on atoms in the fcc Fe1-yNiy was estimated to be a minimum around this composition. The observed variation for the carbon solubility and the extent of stabilisation of the carbon atoms in the fcc Fe1-yNiy latti ce with respect to the composition y appeared to be related to the sta bility of the ferromagnetic phase. (C) 1996 The Institute of Materials .