Manufacturing and Thermal Shock Characterization of Porous Yttria Stabilized Zirconia for Hydrogen Energy Systems

Abstract

Porous yttriastabilized zirconia (YSZ), in a composite with NiO, is widely used as a cermet electrode in solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs). Given cycles of high temperature in these energy devices, mechanical integrity of the porous YSZ is critical. Pore morphology, as well as properties of the ceramic, ultimately affect the mechanical properties of the cermet electrode. Here, we fabricated porous YSZ sheets via freezing of an aqueous slurry on a cold thermoelectric plate and quantified their flexural properties, both for as-fabricated samples and samples subjected to thermal shock at 200 °C to 500 °C. Results of this work have implications for the hydrogen economy and global decarbonization efforts, in particular for the manufacturing of SOFCs and SOECs.

Localized Electrochemical Repair (LER) of Conductive Materials

“…As a comparison, Weibull modulus of 5.7 and 3.7 has been reported for porous yttria stablized zirconia (YSZ) and polymer‐derived ceramics, respectively. [ 38,39 ]…”

“…As a comparison, Weibull modulus of 5.7 and 3.7 has been reported for porous yttria stablized zirconia (YSZ) and polymer-derived ceramics, respectively. [38,39] Having produced the ceramic preforms, the next stage encompassed the fabrication of MMC through electrodeposition to infiltrate Cu into the porous alumina preform. [23] This process employed a commercial Cu sulfate electrolyte.…”

3D-Printed Ceramics with Aligned Micro-Platelets

“…For ceramic materials, Weibull analysis is preferred given the stochastic nature of failure in these materials arising from process defects and porosity. The probability of failure can be expressed as P normalf = 1 − exp true( prefix− σ σ 0 true) m , where m is the Weibull modulus, and σ 0 is the characteristic strength. , The Weibull modulus is a shape parameter that converts a specimen’s likelihood of failure over a range of strength levels. For the analysis, the flexural strength values of the specimens were ranked in ascending order and assigned a corresponding probability of failure using P f = ( i – 0.5)/ N , where P f is the rank of the i th specimen and N is the total number of tested specimens.…”

“…, where m is the Weibull modulus, and σ 0 is the characteristic strength. 18,40 The Weibull modulus is a shape parameter that converts a specimen's likelihood of failure over a range of strength levels. For the analysis, the flexural strength values of the specimens were ranked in ascending order and assigned a corresponding probability of failure using P f = (i − 0.5)/N, where P f is the rank of the i th specimen and N is the total number of tested specimens.…”

“…Although a relatively high strength for the porosity level was obtained, the obtained Weibull modulus, m, is on the lower range of that for porous ceramics. 40 A higher value of Weibull modulus is attributed to the lower variability in the measured strength (flaws are consistent and evenly distributed), while a low Weibull modulus is an indication of higher variability in the samples (flaws are clustered inconsistently). This variability is attributed to the distribution of physical flaws and defects within the sample, given that the brittle failure originates at defects and points of stress concentration.…”