Aj. Allen et al., Microstructural characterization of yttria-stabilized zirconia plasma-sprayed deposits using multiple small-angle neutron scattering, ACT MATER, 49(9), 2001, pp. 1661-1675
Density, electron microscopy, elastic modulus, and small-angle neutron scat
tering studies are used to characterize the microstructures of yttria-stabi
lized zirconia plasma-sprayed deposits as a function of both feedstock morp
hology and annealing. In particular, anisotropic multiple small-angle neutr
on scattering data are combined with anisotropic Pored scattering results t
o quantify each of the three main porous components in these thermal barrie
r coating materials: intrasplat cracks, intersplat lamellar pores and globu
lar pores. An inverse correlation between the volume of porosity and its su
rface area is confirmed for the as-sprayed deposits, as is a preferential a
nnealing of intrasplat cracks at elevated temperatures. The average elastic
modulus is correlated with the total void surface area while the elastic a
nisotropy is related more closely to the intersplat porosity. However, depe
nding on the feedstock morphology, globular pores are also shown to play a
surprisingly significant role in post-anneal deposit microstructures and pr
operties. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd.
All rights reserved.