Elastic Constants for X-Ray Stress Measurement of Ceramics for Solid Oxide Fuel Cell (SOFC)
Keisuke TANAKA, Yoshihisa DOI, Yoshiaki AKINIWA, Hirofumi SUMI, Yasunobu MIZUTANI and Kenji UKAI
Abstract:The mechanical and X-ray elastic constants of ceramics used for solid oxide fuel cells (SOFCs) were measured and compared with the predictions based on the models of elastic deformation of polycrystals and multiphase materials. The elastic compliances of single crystal of scandia stabilized zirconia (10ScSZ) for electrolyte were determined from the experimental values of X-ray elastic constants as follows: s11 = 2.21 Tpa-1, s12 = -0.10 Tpa-1, s44 = 24.5 Tpa-1D The X-ray elastic compliances increase with the orientation function. The X-ray elastic compliances for doublet peaks can be obtained from those of each peak and the intensity ratio. The experimental values of the mechanical elastic constants of anode composed of zirconia and nickel (Ni-3YSZ) or nickel oxide (NiO-3YSZ) agreed fairly well with the prediction based on the self consistent model. The experimental values of the X-ray elastic constants of anode showed about 10 to 15 % deviation from the prediction based on the self consistent model, because of the inhomogeneous mixture of zirconia and nickel (or nickel oxide). The experimental determination of the X-ray elastic constants was recommended for X-ray stress analysis of anode. Key Words:X-ray stress measurement, X-ray elastic constant, Solid oxide fuel cell, SOFC, Zirconia, Anode, Internal stress