Abstract:

Oliver Pharr method may overestimate the hardness because of the effect of pile up. In this paper, the mechanical properties of oxide fuel cell, such as hardness and elastic modulus, are determined by a work of indentation, then a reverse analysis algorithms is followed to analyze the yield strength. From the nanoindentation tests carried out for the half-cell structure of solid oxide fuel cells (SOFCs), the typical mechanical properties are derived by the work of indentation and the reverse analysis algorithms. Due to the differences of Young's modulus and the mismatch of thermal expansion coefficients in the half-cell structure (NiO-YSZ/YSZ), the residual stress, which has effects on the fuel cell's performance, is aroused during sintering. Numerical results show that the load-displacement curve is agreement with the experimental curve if the residual stress was considered.

Key words: Solid oxide fuel cell, Residual stress, Nanoindentation, Yield strength, Reduction