スモールパンチ試験による固体酸化物形燃料電池用セラミックス薄板の静的強度に関する研究

抄録

Small Punch (SP) tests were carried out for the ceramics thin plates for use in Solid Oxide Fuel Cell. As a result of SP tests, the fracture strength decreases with decreasing crosshead speed. The reason for decreasing fracture strength is the delayed fracture. Also, the fracture strength slightly increases with decreasing dimension of specimen. The specimen size almost has no effect on the fracture strength. Next, it was possible to measure a Young's modulus of the ceramics thin plates except for that with the small deflection. Three-dimensional SP model which introduced the semicircle crack as a preexistence defect was made, and the FEM analysis was carried out. In the case of φ10mm × 10mm specimen, there is a case in which stress intensity factor of semicircle crack on the indentation plane is larger than that on the back side. Therefore, there is a high probability that the specimen is fractured from preexistence defect in the indentation plane side of specimen. For that, it is necessary to decrease the thickness of specimen.