Abstract
This study is to evaluate the thermal shock fracture reliability of partially stabilized zirconia components in laser heating. To elucidate the thermal shock cracking, the stress distribution and the thermal stress intensity factor are analyzed using the finite element method, and the results of analysis are compared with the thermal shock experiments by the laser heating. From the analysis, it seems that the maximum principal stress direction shifts from the Z-axis direction under the irradiated surface to the tangential direction outside the irradiated area. As the irradiation energy increases, the thermal stress intensity factor increases. On the other hand, some experimental results show that the thermal crack is initiated on the surface and propagates to the radial direction of the irradiated area, although the cracking is arrested after the critical length. Also, there is no crack initiation below the critical irradiation energy. These observed cracking behavior corresponds with the analytical results. Finally, the thermal shock fracture toughness is obtained from the critical irradiation energy and the thermal stress intensity factor analysis. The thermal shock fracture toughness is smaller than the fracture toughness in the same temperature.
