Kinetics study of the spinodal decomposition in the Fe-30.8Cr-12.2Co alloyby Mossbauer spectrometry

The phase transformation in the Fe-30.8Cr-12.2Co alloy has been studied by Mossbauer spectrometry as a function of the aging time at the temperatures 520, 560 and 600 degrees C. It is found that the transformation occurs with out any incubation time, consistent with a spinodal decomposition and that the average hyperfine field increases indicating changes of iron environmen ts. The decomposition rate is influenced by the aging temperature and incre ases at higher temperatures. The kinetics of transformation can be describe d by an Avrami parameter smaller than 0.2 and a value of the activation ene rgy close to 17 kJ mol(-1). (C) 1999 Elsevier Science S.A. All rights reser ved.