3D Analysis of Porosity in a Ceramic Coating Using X-ray Microscopy
Artikel i vetenskaplig tidskrift, 2017
Suspension plasma spraying (SPS) is a new,
innovative plasma spray technique using a feedstock consisting of fine powder particles suspended in a liquid. Using SPS, ceramic coatings with columnar microstructures have been produced which are used as topcoats in thermal barrier coatings. The microstructure contains a wide pore size range consisting of inter-columnar spacings, micro-pores and nano-pores. Hence, determination of total porosity and pore size distribution is a challenge. Here, x-ray microscopy (XRM) has been applied for describing the complex
pore space of the coatings because of its capability to
image the (local) porosity within the coating in 3D at a
resolution down to 50 nm. The possibility to quantitatively
segment the analyzed volume allows analysis of both open
and closed porosity. For an yttria-stabilized zirconia coating with feathery microstructure, both open and closed
porosity were determined and it could be revealed that 11%
of the pore volumes (1.4% of the total volume) are closed
pores. The analyzed volume was reconstructed to illustrate
the distribution of open and closed pores in 3D. Moreover,
pore widths and pore volumes were determined. The results
on the complex pore space obtained by XRM are discussed
in connection with other porosimetry techniques.
porositypore size distributionsuspension plasma spray
TBC
yttria-stabilized zirconia
x-ray microscopy
topcoat