Hot-gas-jet method and apparatus for thermal-shock testing

The hot-gas thermal shock testing method consists of impinging a stream of high temperature air onto the center of a ceramic disk. This test is suitable for determining the relative resistance of ceramics to thermal shock involving fast heating from ambient with the principal heat transfer mode being convection. The feasibility of this testing method has been established using specimens of transparent La2O3-doped Y2O3. Thermal shock fracture appears to initiate from the backface of the disk. Thinner or toughened transparent Y2O3 results in a higher probability of survival for a given critical temperature difference in the test.