Thermodynamics of iron‐chromium alloys: Mass spectrometric determination of the excess properties in the bbc phase and calculation of the phase diagram

Abstract

Thermodynamic excess properties of iron-chromium alloys in the bcc phase have been investigated by Knudsen cell mass spectrometry in the temperature range 1470-1750 K. The molar excess Gibbs energies, entropies and heats of mixing as well as the thermodynamic activities were determined from the ion intensities as a function of composition by fitting to a sub-regular solution model (2 parameter T. A. P.

The system Fe–Ni–Cr: revision of the thermodynamic description

“…By means of newer mass spectrometric investigations on bcc solid Cr-Fe alloys by [12] molar excess Gibbs energies G E have been determined which are distinctly different to the values of the assessments by Anderson and Sundman [20] and Lee [9]. But, as can be seen from Fig.…”

“…(b) Ni-Cr (experimental points (for references see [13]) (᭺); [13] (-)). (c) Cr-Fe (experimental points (for references see [12]) (᭺); this work (-); Hillert and Qiu [8]; Lee [9] (· · · )). because in case of multicomponent alloy systems such as the Fe-Ni-Cr ternary system including the three binary boundary systems the thermodynamic investigations for the determination of reliable molar Gibbs energy data are very time-wasting, and usually beset with considerable experimental difficulties.…”

“…The synthesis of the phase relations of this work is also based upon these melting points of the three constituents. In [12] the experimental phase diagram data of Cr-Fe at temperatures higher than the melting point of Fe have been raised proportional to the old and new differences of the melting points of the constituents, therefore. This causes some discrepancies to the figures as presented in the original literature.…”

Mass spectrometric determination of the thermodynamic excess properties of ternary Fe–Co–Cr melts

“…a From mass spectrometric investigations. b Assessed by means of phase boundary calculations based upon mass spectrometric investigations of the bcc phase in [10].…”

“…For liquid Fe-Co-Cr alloys all three binary boundary systems are well-established in literature. The Fe-Co [8] and Co-Cr [9] melts have been determined mass-spectrometrically, and the TAP parameters of liquid Cr-Fe alloys have been assessed by means of phase boundary calculations based upon experimental data of the bcc phase [10]. The resultant molar excess Gibbs energies of all three binary boundary systems have been used successfully for the calculations of the binary phase diagrams [9][10][11].…”