Image analysis and modeling of the orientation of pores in a constrained film on a rigid substrate

The nature of porosity in functional materials is often a critical parameter in determining their functionality, for example, in structure materials and fuel cell electrodes. Here, we study the development of the anisotropy of porous yttria-stabilized zirconia (YSZ), focusing particularly upon the contribution of pore orientation to this anisotropy. Simulation from when the ink is deposited on the surface of a rigid substrate shows that platelike pores are found tend to align along the transverse direction of the substrate. Cross-sectional image analysis of the pores from the attendant pores of YSZ particles or pore-forming agent (PFA) matches with the simulated modeling when materials transport is insignificant in determining the shape of pores. The anisotropy created in the densification stage is separated from that in the green body by analyzing the image of porous structures formed with spherical glassy carbon which is unable to contribute to anisotropy during green-state processing.