Laser induced creep and fracture in ceramics

In order to find ways of suppressing damage of thermal barrier coatings, a few well-defined partial problems have been investigated experimentally and theoretically: crack formation due to high temperature creep, measurement of creep properties by laser shock, formation of layer and spalling cracks, and fracture mechanics analysis of the normal/spalling transition. The creep parameters of the material are derived from the residual surface uplift after local heating. It is shown how the numerical effort for solving the involved creep problems can be reduced by applying suitable approximations. The expected depth of spalling fracture is estimated by considering the stress intensity factor KII.