Journal Article

IMPULSE-2025-00132

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png High-temperature compression induced α to γ phase transformation and related phase morphology transition in TiAl alloy

Keïta, M. ; Solís, C.MLZ* ; Gan, W.MLZ* ; Siredey-Schwaller, N. ; Moulin, J.-F.MLZ* ; Zhang, Y. (Corresponding author) ; Bouzy, E.

2025
Elsevier Lausanne

Please use a persistent id in citations: doi:10.1016/j.jallcom.2025.184044

Abstract: Titanium aluminide (TiAl) alloys are promising for aerospace and automotive applications due to their low density, high strength and excellent oxidation and creep resistance. Among them, the β-solidifying TNM (Ti-Al-Nb-Mo-B) alloys exhibit remarkable mechanical properties and thermal stability. Hot deformation is commonly used to shape these alloys, typically below the (α + β) phase region (below the γ-solvus temperature). In this study, hot compression was performed at 1280 ◦C (in the (α + β) phase region) with two thickness reductions at a strain rate of 10-2 s-1. Unexpectedly, the γ phase resurged abnormally from the α phase despite its thermodynamic instability at equilibrium. The formed γ phase follows the Blackburn orientation relationship (OR) and exhibits lamellar and nodular morphologies. Crystallographic analysis reveals that the activation of the basal slip in the α phase under the compression triggered this transformation. The early formed γ lamellae then evolved through fragmentation, spheroidization, coarsening and boundary sliding, leading to the morphology change from lamellae to nodules. These insights advance the understanding of TNM alloys for high-performance and hightemperature applications.

Keyword(s): Engineering, Industrial Materials and Processing (1st) ; Materials Science (2nd) ; Industrial Application (2nd)

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Contributing Institute(s):

1. HEREONLAB (MATSCILAB ; HEREONLAB)
2. STRESSI (STRESSI)
3. REFSANS (REFSANS)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2025

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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