Citation:
R. G. Wellman, J. R. Nicholls, Some observations on erosion mechanisms of EB PVD TBCS, Wear, Volume 242, Issues 1-2, 10 July 2000, Pages 89-96
Abstract:
Following the successful application of electron beam (EB) physical vapour
deposition (PVD) thermal barrier coatings (TBCs) to moving parts of turbine
engines, the erosion resistance of these coatings has been of interest among
researchers. However, although there are a number of papers on the erosion rate
of these coatings, little has been reported on their erosion mechanism. This
paper provides observations on the erosion damage of EB PVD TBCs and discusses
the type of damage caused by erosion, as well as proposing a possible mechanism
of erosion. The aim of the project as a whole was to model the erosion of EB PVD
TBCs, but before modelling could begin, it was necessary to determine the
erosion mechanism of these coatings. It was found that in all cases examined,
the erosion of the coatings proceeds through the accumulation of damage in the
form of horizontal cracks in the columns of the coating and subsequent removal
of the fractured sections. Since it appears as though the contact radius is
important in the erosion process, the effect of varying the elastic properties
of the erodent and the target on the contact radius was assessed.
