In Situ Observation of the Competition Between Metastable and Stable Phases in Solidification of Undercooled Fe-17at. pctB Alloy Melt

Di Zhang, Junfeng Xu, Feng Liu

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

High-speed video (HSV) technique was used to investigate the solidification behavior of undercooled Fe-17at. pctB alloy melt. Competitive growth between Fe/Fe3B (metastable eutectic) and Fe/Fe2B (stable eutectic) was captured, which is correlated with the critical nucleation undercooling ΔTn[=104 K (104 °C)] and the critical growth undercooling ΔTg[=151 K~183 K (151 °C~183 °C)]. For the initial undercooling, ΔT<ΔTn, only the stable eutectic reaction (L → Fe/Fe2B) occurs during solidification, whereas, for ΔT>ΔTn, the metastable eutectic reaction (L → Fe/Fe3B) occurs firstly, followed by the stable eutectic reaction. Nevertheless, ΔT>ΔTn does not guarantee that the metastable phase (Fe3B) appears finally. Only if ΔT>ΔTg, Fe3B phase can be found in the room microstructure, as the growth velocity of metastable eutectic (Fe/Fe3B) is larger than stable eutectic (Fe/Fe2B) from HSV results; otherwise, the final structure consists of Fe2B and α-Fe. Accordingly, not only the competitive nucleation, but the competitive growth also determines the final microstructure of Fe-17at. pctB alloy.

Original languageEnglish
Pages (from-to)5232-5239
Number of pages8
JournalMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Volume46
Issue number11
DOIs
StatePublished - 1 Nov 2015

Fingerprint

Dive into the research topics of 'In Situ Observation of the Competition Between Metastable and Stable Phases in Solidification of Undercooled Fe-17at. pctB Alloy Melt'. Together they form a unique fingerprint.

Cite this