Residual Stress Measurement of a Single-step Sintered Planar Anode Supported SC-SOFC Using Fluorescence Spectroscopy

Abstract

The fluorescence spectroscopy technique was used to measure the residual stress between the cathode and electrolyte of an anode supported planar single-chamber solid oxide fuel cell. The cell was made of (NiO-CGO) :(CGO) :(LSCF-CGO), as anode:electrolyte:cathode and the test was carried out after sintering at room temperature. The measured stress between these layers arises from the sintering stress caused by differential shrinkage from layers during sintering and the thermal expansion co-efficient mismatch between the layers during cooling. Therefore, the residual stress in the cathode and electrolyte layer of the cell due to co-efficient of thermal expansion mismatch during cooling was calculated analytically so as to find sintering stress. According to findings a maximum compressive residual stress of -1084 MPa occurred at the place contiguous to electrolyte layer. The estimated residual stresses in the cell’s cathode and electrolyte layer owing to CTE mismatch for the duration of cooling was calculated as -324 MPa and 15.96 MPa, respectfully. Furthermore, total mean residual compressive stress between cathode and electrolyte was obtained from fluorescence spectroscopy as -703.795. Thus, the main contribution of this residual stress is the stress growth during sintering (-395.755 MPa) due to different shrinkage behavior of adjacent layers.