Ingeniare. Revista chilena de ingeniería
versão On-line ISSN 0718-3305
PALACIO ESPINOSA, Claudia Constanza. Mechanical responses of plasma sprayed coatings from residual stress measurements and finite element analysis: effect of the pore network architecture. Ingeniare. Rev. chil. ing. [online]. 2011, vol.19, n.3, pp. 323-335. ISSN 0718-3305. http://dx.doi.org/10.4067/S0718-33052011000300003.
This study aims a better understanding residual stress and stress field within composite plasma sprayed coatings submitted to strains. In order to reach out this objective, residual stress techniques can be implemented for measurements during elaboration of coatings and finite element analyses (FEA) can be conducted on domains resulting from the discretization of Scanning Electron Microscopy (SEM) high resolution pictures of coating structures. TiO2-Cu and Al2O3-HTiO2 plasma sprayed coatings were considered for demonstrative purposes regarding residual stress measurements and effect of the pore network architecture, respectively. Several operating parameters permitted to manufacture coatings exhibiting different magnitude of residual stress and several porous architectures, in terms of pore content, crack density and crack orientation. Residual stress determined from measurements of deflection during elaboration of TiO2-Cu coatings allow to identify their nature while numerical simulations show the very significant influence of the network architecture on the stress field within the Al2O3-13TiO2 coatings. Based on the same analyzed structures, other theoretical compositions were considered in the finite element analyses by modifying the intrinsic mechanical properties of the phases. For the considered cases, simulations show the poor influence of the nature of the secondary phase on the stress field within the coatings. Beside these results, the paper proposes a generic methodology and points out its advantages and limits, emphasizing in particular the importance of the representative elementary volume (REV).
Palavras-chave : Plasma coatings; mechanical properties; deflection; finite element analysis; microstructure.