Scale dependence of the Young's modulus measured by nanoindentation in columnar YSZ EB-PVD thermal barriers coatings

Abstract

Electron beam-physical vapour deposited (EB-PVD) yttria-stabilized zirconia (YSZ) thermal barrier coatings have been investigated by nanoindentation. It is shown that the mechanical properties, and particularly the Young's modulus, of these coatings are closely related to their columnar microstructure. The transition from intracolumnar to intercolumnar deformation is characterized by a difference between the mechanical properties of the bulk YSZ and those of the coatings. The use of different indenter shape showed that the contact area was the parameter characteristic of this scale dependence. Deformation mechanisms studied by AFM have shown a good correlation with the evolution of the mechanical properties during the deformation.

Acknowledgements

Work supported by the European Community's Human Potential Programme under contract HPRN-CT-2002-00203, [SICMAC]. Y.G. acknowledges the financial support provided through the European Community's Human Potential Programme under contract HPRN-CT-2002-00203, [SICMAC]. The authors acknowledge Marion Bartsch for providing the EB-PVD specimens.