Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8028317 | Surface and Coatings Technology | 2014 | 10 Pages |
Abstract
The stress state and failure mechanisms of thermal barrier coating systems are frequently studied using finite element simulations. One problem in evaluating the results of such simulations is that the material behaviour of the top coat and especially of the thermally grown oxide is not well-known. Either plasticity or viscoplasticity is frequently assumed to be the dominating stress relaxation mechanism with the implicit assumption that both mechanisms will lead to similar stress patterns. In this contribution, this assumption is critically evaluated. Different combinations of plasticity or viscoplasticity for the top coat and the TGO are studied. If viscoplasticity is not present, the stress evolution is dominated by plastic ratchetting, but this is counteracted by creep relaxation if the creep strength is sufficiently low.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
M. Bäker,