Sand infiltration was investigated for several yttria-stabilized zirconia (YSZ) pellets of varying porosity. The pellets were synthesized through either pressureless spark plasma or cold sintering. As-sintered pellets were exposed to molten and semi-molten synthetic sand for approximately 15 min each. Several characterization techniques were used to correlate the sand infiltration to porosity. It was found that there was no significant difference in the results of low and high porosity samples. Interestingly, sand had infiltrated all samples to some degree although the magnitude of the infiltration did not appear to be related to the porosity. Electron micrographs of a low-porosity sample indicate an infiltration mechanism through the YSZ grain boundaries. X-ray diffraction detected the presence of quartz, which is seen to add strain into the system. Lastly, isotropy and surface roughness tests suggest a general increase in both parameters in all samples but no difference was seen between the high and low porosity samples. Possible mechanisms include infiltration through the grain boundaries and a reactive grain boundary-like mechanism due to Y3+ leaching out of the YSZ crystal structure to form a yttrium silicate phase.
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