Strain-induced interaction of dissolved atoms in γ-Fe

• Published in: Journal of alloys and compounds 1999-09, Vol.291 (1), p.167-174
• Main Author: Blanter, M.S.
• Format: Article
• Language: English
• Subjects: Austenite; Elastic interaction; Gamma-Fe; Strain-induced interaction; Thermodynamical activity
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/S0925-8388(99)00255-8

The energies of strain-induced (elastic) interaction of interstitial–interstitial (i–i), interstitial–substitutional (i–s) and substitutional–substitutional (s–s) pairs are calculated for γ-Fe at 1428 K with account of discrete atomic structure of the host lattice. The elastic constants, lattice spacing, Born–von Karman constants of the host lattice, and coefficients of the concentration expansion of the solid solution lattice due to solute atoms are the input numerical parameters used. The interaction is oscillating, anisotropic and in some solid solutions strong and long-range. In all γ-Fe-base solid solutions there is attraction in some coordination shells. Generally, the strain-induced interaction in γ-Fe is weaker than in α-Fe but in some solid solutions it may be of the same order. The verification of applicability of the model of strain-induced interaction for carbon austenite by means of calculation of carbon activity and the parameters of carbon distribution given by Mössbauer spectroscopy showed that it must be supplemented by additional repulsion in the first coordination shell. The strain-induced interaction must be taken into account for analysis of structure and properties of γ-Fe-base solid solutions.