Journal of Thermal Spray Technology

, Volume 16, Issue 5, pp 798–803

Effects of Impurity Content on the Sintering Characteristics of Plasma-Sprayed Zirconia

Authors

    • Department of Materials Science & MetallurgyCambridge University
  • A. Cipitria
    • Department of Materials Science & MetallurgyCambridge University
  • I.O. Golosnoy
    • Department of Materials Science & MetallurgyCambridge University
  • L. Xie
    • Sulzer Metco (US) Inc.
  • M.R. Dorfman
    • Sulzer Metco (US) Inc.
  • T.W. Clyne
    • Department of Materials Science & MetallurgyCambridge University
PEER REVIEWED

DOI: 10.1007/s11666-007-9097-5

Cite this article as:
Paul, S., Cipitria, A., Golosnoy, I. et al. J Therm Spray Tech (2007) 16: 798. doi:10.1007/s11666-007-9097-5

Yttria-stabilized zirconia powders, containing different levels of SiO2 and Al2O3, have been plasma sprayed onto metallic substrates. The coatings were detached from their substrates and a dilatometer was used to monitor the dimensional changes they exhibited during prolonged heat treatments. It was found that specimens containing higher levels of silica and alumina exhibited higher rates of linear contraction, in both in-plane and through-thickness directions. The in-plane stiffness and the through-thickness thermal conductivity were also measured after different heat treatments and these were found to increase at a greater rate for specimens with higher impurity (silica and alumina) levels. Changes in the pore architecture during heat treatments were studied using Mercury Intrusion Porosimetry (MIP). Fine scale porosity (<50 nm) was found to be sharply reduced even by relatively short heat treatments. This is correlated with improvements in inter-splat bonding and partial healing of intra-splat microcracks, which are responsible for the observed changes in stiffness and conductivity, as well as the dimensional changes.

Keywords

apparent Young’s modulusplasma spray coatingsporous materialsinteringthermal conductivity

Copyright information

© ASM International 2007