Isochronal phase transformations in melt-spun Fe-B system

Moessbauer effect is a powerful tool for phase identification. The measurements with this technique indicate that the as-quenched Fe/sub 86/B/sub 14/ and Fe/sub 83/B/sub 17/ alloys are mainly amorphous while Fe/sub 88/B/sub 12/ and Fe/sub 72/B/sub 28/ alloys are crystalline with some amorphous phase. For the study of phase transitions, these samples have been isochronally heat treated at a rate of 40 K/hour, with on way quenching at various temperatures, up to 1000 K. The Moessbauer measurements indicate the generation and their transformation on heat treatment to the phase not present in the as-quenched samples. In Fe/sub 86/B/sub 14/ and Fe/sub 88/B/sub 17/ the phase transition sequence is found to comprise three regions viz. structural relaxation region, crystallization region and structure coarsening region. In each region the phases involved are different. On the other hand, in crystalline compositions no such regions are observed. (author)