On the miscibility gap at 800 K in the Fe-Cr alloy system

TL;DR

This study investigates the phase decomposition kinetics and solubility limits in an Fe-Cr alloy at 800K using Mössbauer-effect spectroscopy, revealing nucleation and growth mechanisms and comparing results with theoretical models.

Contribution

It provides new experimental data on the miscibility gap and phase decomposition kinetics in Fe-Cr alloys at 800K, using Mössbauer spectroscopy.

Findings

Kinetics follow Johnson-Mehl-Avrami-Kolgomarov equation

Cr solubility limit in Fe matrix is 17.3(6) at.%

Fe solubility limit in Cr matrix is 18.5(9) at.%

Abstract

Issues pertinent to the miscibility gap at 800K in a Fe73.7Cr26.3 alloy viz. the kinetics of the phase decomposition and borders of the latter were investigated by means of the M\"ossbauer-effect spectroscopy. The kinetics was revealed to well follow the Johnson-Mehl-Avrami-Kolgomarov equation testifying to a nucleation and growth mechanism underlying the decomposition. A solubility limit of Cr in the Fe matrix was determined to be 17.3(6) at.% and that of Fe in the Cr matrix was found as equal to 18.5(9) at.%. The results obtained have been compared with various theoretical predictions.