Functionally graded Al2O3‐based ceramic systems by gel casting method

Abstract

AbstractFunctionally graded ceramic systems consisted of Al2O3/(Al2O3–ZrO2) and Al2O3/(Al2O3–Nd2Ti2O7) have been produced by gel casting. In Al2O3/ZrO2 systems, Al2O3 was gathered with three different Al2O3/ZrO2 mixtures with varying ZrO2 contents. For Al2O3/Nd2Ti2O7 system, Al2O3 layer was combined with 3 mol% Nd2Ti2O7‐doped Al2O3. All samples sintered at 1480 and 1540°C showed strong adhesion between layers without any crack formation. In the Al2O3/ZrO2 systems, both layers were intact; a distinct separation was observed, whereas a large reaction zone was observed for the Al2O3/Nd2Ti2O7 system as a consequence of reaction between both phases. The separation between layers for both systems was identified by SEM–EDX analyses. The hardness and wear tests of the samples showed that functional grading approach ensures combining various physical properties in a monolithic body.