%0 Journal Article
%A Bakan, Emine
%A Vaßen, Robert
%T Crack healing mechanisms in atmospheric plasma sprayed Yb-silicate coatings during post-process heat treatment
%J Journal of the European Ceramic Society
%V 43
%N 8
%@ 0955-2219
%C Amsterdam [u.a.]
%I Elsevier Science
%M FZJ-2023-01375
%P 3684-3693
%D 2023
%X The microstructural evolution of partially amorphous, atmospheric plasma-sprayed Yb-silicate coatings was investigated after heat treatment (HT, 1300 °C). Open porosity as well as crack area and widths in the coatings were characterized. A correlation was found between the increasing amorphous content of the as-sprayed coatings and the reduction in crack area due to crack healing after HT. Characterization results also suggested larger crack widths in the coatings after HT. The first crack-healing mechanism proposed was the capillarity-driven viscous flow of the amorphous phase in the coatings. It was experimentally shown that viscous flow-driven crack spheroidization (crack width enlargement), and crack healing started in the coatings at 1050 °C. Secondly, metastable to stable phase transformation (> 1100 °C) induced expansion in the constrained coatings was discussed as a crack healing mechanism. Finally, a two-step heat treatment was designed to prevent crack width enlargement during HT resulting in reduced porosity.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000951698900001
%R 10.1016/j.jeurceramsoc.2023.02.005
%U https://juser.fz-juelich.de/record/1005227