An analysis of unsteady thermal stresses in a functionally gradient ceramic plate with symmetrical structure

The analytical formulae of one-dimensional unsteady temperature field and unsteady thermal stress field for a functionally gradient material plate with symmetrical structure were derived by using perturbation method, by which the unsteady temperature fields and unsteady thermal stress fields of an Al2O3/(W,Ti)C functionally gradient ceramic plate with symmetrical structure were calculated in case of both surface cooling and surface heating. The results obtained showed that the absolute values of thermal stresses of the functionally gradient ceramic plate are lower than those of the homogeneous ceramic plate for both surface cooling and surface heating cases. Hence an approach to improving the thermal shock resistance of ceramic tool materials i.e. using functionally gradient ceramic tool materials, was put forward and verified by intermittent turning of hardened tool steel.