Journal Article

PUBDB-2018-03646

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png New insights into perovskite-Ti$_{3}$AlC precipitate splitting in a Ti-45Al-5Nb-0.75C alloy by transmission electron microscopy

Wang, L. (Corresponding author)Extern* ; Oehring, M. ; Lorenz, U. ; Stark, A.Extern* ; Pyczak, F.Extern*

2018
Elsevier Science Amsterdam [u.a.]

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Please use a persistent id in citations: doi:10.1016/j.intermet.2018.06.006  doi:10.3204/PUBDB-2018-03646

Abstract: The addition of carbon in TiAl alloys can improve the mechanical properties by precipitate hardening through the perovskite Ti$_3$AlC carbide. Usually precipitates coarsen during continuous annealing. However, in the Ti-45Al-5Nb-0.75C alloy a splitting of the perovskite carbides was observed in later stages of annealing. By investigation with transmission electron microscopy the details of this splitting process are revealed after annealing at 900 °C. The results show that the re-orientation of the $γ$ phase regions between sub-particles is associated with the splitting step from carbide needles into small sub-particles. $γ$ domains with a different orientation with respect to the $γ$ matrix nucleate and gradually replace the $γ$ matrix phase in regions between the carbide sub-particles. The progress of the splitting process is locally different in different carbides and also in one individual carbide. By increasing the temperature from 800 to 900 °C the growth of the emerging carbide conglomerates and the splitting process of the carbides are greatly accelerated. It is found that both are diffusion-controlled processes.

Note: © Elsevier B.V.

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Contributing Institute(s):

1. DOOR-User (DOOR)
2. Zentrum für Material- und Küstenforschung (HZG)

Research Program(s):

1. 6G3 - PETRA III (POF3-622) (POF3-622)

Experiment(s):

1. DORIS Beamline W2 (DORIS III)
2. PETRA Beamline P07 (PETRA III)

Appears in the scientific report 2018

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Database coverage:
; ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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