%0 Journal Article
%A Wang, Li
%A Zenk, Carolin
%A Stark, Andreas
%A Felfer, Peter
%A Gabrisch, Heike
%A Göken, Mathias
%A Lorenz, Uwe
%A Pyczak, Florian
%T Morphology evolution of Ti<sub>3</sub>AlC carbide precipitates in high Nb containing TiAl alloys
%J Acta materialia
%V 137
%@ 1359-6454
%C Amsterdam [u.a.]
%I Elsevier Science
%M PUBDB-2017-14130
%P 36 - 44
%D 2017
%X This work elucidates the morphology evolution of perovskite Ti<sub>3</sub>AlC carbides in a Ti-45Al-5Nb-0.75C alloy during ageing at 800 °C. The carbides in the γ matrix are initially needle-shaped with their long axis parallel to the [001] lattice direction of the γ matrix. After extended annealing, they decompose into small carbide sub-particles. By combining different transmission electron microscopy characterization methods and atom probe tomography it has been verified that the carbides first split into several parallel needles that are aligned along the [001]γ lattice direction. Later these parallel needles further decompose into numerous small sub-particles, while the matrix phase region between the sub-particles crystallographically reorients. To the authors' knowledge this is the first work which demonstrates such a precipitate splitting process in a matrix with a tetragonal crystal structure. It is proposed that the decomposition into small sub-particles is energetically favourable owing to the elastic interaction energy between the split sub-particles.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000408596600004
%R 10.1016/j.actamat.2017.07.018
%U https://bib-pubdb1.desy.de/record/398566