TY - JOUR
T1 - In Situ Observation of the Competition Between Metastable and Stable Phases in Solidification of Undercooled Fe-17at. pctB Alloy Melt
AU - Zhang, Di
AU - Xu, Junfeng
AU - Liu, Feng
N1 - Publisher Copyright:
© 2015, The Minerals, Metals & Materials Society and ASM International.
PY - 2015/11/1
Y1 - 2015/11/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84942987235&partnerID=8YFLogxK
U2 - 10.1007/s11661-015-3104-0
DO - 10.1007/s11661-015-3104-0
M3 - 文章
AN - SCOPUS:84942987235
SN - 1073-5623
VL - 46
SP - 5232
EP - 5239
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
IS - 11
ER -