Residual stress in plasma sprayed zirconia on cylindrical components

This paper present a finite element model able to predict the residual stress in a plasma sprayed cylindrical components, as used in foundry applications. The studied coating is a zirconia (ZrO 2) stabilised with 25% ceria (CeO) and 2–3% yttria (Y 2O 3), deposited by plasma spraying on a chromium–molybdenum–vanadium tool steel. The main problem in stress field measurement for ceramic coatings results from their typical morphology, characterised by voids and microcracks. This type of morphology leads to great scatter in residual stress measurement in almost any kind of plasma deposited ceramic coating. Analytical methods can be used to evaluate the residual stresses field, but these methods fail also to predict the effect of discontinuities and moreover, this approach does not take into account the specific morphology of the coating. The residual stresses values calculated by the numerical simulation are in very good agreement with the experimental results obtained by neutron diffraction in the substrate, and satisfactory for measurements in the ceramic layer. Therefore, the presented model can be used to predict the residual stress distribution in ceramic plasma coated cylindrical components.