ISOCHROMAT SPECTROSCOPIC INVESTIGATION OF THE HCP-BCC PHASE TRANSFORMATION OF TITANIUM, ZIRCONIUM, AND HAFNIUM

In-situ observations of a/g phase transformation were made to study the effect of grain boundary microstructure of the generation of a new phase and the migration of a/g interphase boundaries in an Iron-4.2at.%Cr alloy. It was found that triple junctions with more random boundaries could be the primary nucleation sites, while triple junctions with low angle and low S coincidence boundaries did not play a role as preferential sites. The migration of a/g interphase boundaries during heating across the transformation temperature showed the two stage behaviour characterized first by a stage with a migration velocity of 0.33-0.75µm/s and secondly a stage with 3.7-7.6 µm/s. It was also found that abnormal grain growth and a high density of S3 coincidence boundaries could occur in the a/bcc phase after cycling of a/g/ a phase transformation.

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Orientation Relationship in Fcc–Bcc Phase Transformation Kinetics of Iron: a Molecular Dynamics Study

ISIJ International ◽

10.2355/isijinternational.50.1211 ◽

2010 ◽

Vol 50 (8) ◽

pp. 1211-1216 ◽

Cited By ~ 20

Author(s):

Shinji Tateyama ◽

Yasushi Shibuta ◽

Toshio Suzuki

Keyword(s):

Molecular Dynamics ◽

Phase Transformation ◽

Orientation Relationship ◽

Transformation Kinetics ◽

Phase Transformation Kinetics ◽

Bcc Phase ◽

Kinetics Of

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The FCC to BCC phase transformation kinetics in an Al0.5CoCrFeNi high entropy alloy

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2017.03.249 ◽

2017 ◽

Vol 710 ◽

pp. 144-150 ◽

Cited By ~ 30

Author(s):

Jun Wang ◽

Sizhe Niu ◽

Tong Guo ◽

Hongchao Kou ◽

Jinshan Li

Keyword(s):

Phase Transformation ◽

High Entropy Alloy ◽

Transformation Kinetics ◽

High Entropy ◽

Phase Transformation Kinetics ◽

Bcc Phase

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Bcc / B2 phase equilibria and phase transformation from B2 to β’ in refractory Nb-X(Pd, Rh, Ir)-Al

MRS Advances ◽

10.1557/adv.2017.60 ◽

2017 ◽

Vol 2 (25) ◽

pp. 1335-1340

Author(s):

T. Yamanouchi ◽

S. Miura ◽

M. Ohno ◽

K. Ikeda

Keyword(s):

Solid Solution ◽

Phase Transformation ◽

Surface Layer ◽

Phase Field ◽

Composition Range ◽

Eutectic Temperature ◽

Two Phase ◽

Wide Composition Range ◽

B2 Phase ◽

Bcc Phase

ABSTRACTFor the improvement of oxidation resistance of Nb-based alloys, PdAl-B2 is expected as Al reservoir for Al2O3 surface layer because it is in equilibrium with Nbss (bcc) phase. However, PdAl forms cracks during casting caused by B2 -> β’ transformation. To suppress B2 -> β’ transformation, Rh, Ru and Ir were chosen as additive elements. It is found that bcc / B2 two-phase field in Nb-Pd-Ir-Al system is limited to be small fraction of Ir, while (Pd,Rh)Al-B2 is in equilibrium with bcc solid solution in a wide composition range and addition of Rh prevents occurrence of B2 -> β’ transformation. Composition range of (Pd,Ru)Al-B2 in equilibrium with bcc phase is wider than (Pd,Ir)Al-B2 but narrower than (Pd,Rh)Al-B2. Rh and Ru addition are also beneficial for improving eutectic temperature of Nb-bcc / B2 aluminide two-phase alloys.

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