Mechanical properties and thermal shock behaviour of an alumina/zirconia functionally graded material prepared by electrophoretic deposition

Mechanical properties of a symmetrical planar functionally graded material (FGM) of Al2O3 + 10% ZrO2/Al2O3 + 30% ZrO2/Al2O3 + 10% ZrO2 prepared by electrophoretic deposition (EPD) and pressureless sintering were studied. Hardness and fracture toughness were measured using indentation methods on cross sections of samples. From the difference between lengths of cracks parallel and perpendicular to layers the residual stresses (arisen due to the thermal expansion coefficient mismatch) were calculated. Thermal shock resistance of particular layers was studied using indentation-quench method. The results were compared to those obtained from a reference non-layered composite material, prepared by the same fabrication technique.