Toward excellent performance of Al2O3-ZrO2 reticulated porous ceramics: New insights based on residual stress

Abstract

In terms of improving properties of reticulated porous ceramics (RPCs) prepared by polymer sponge replica technique, vacuum infiltration process (VI process) is applied to fabricate Al2O3-ZrO2 RPCs with multi-layered struts. This paper focuses on the effect of additives on the rheological properties of Al2O3-ZrO2 slurry. Furthermore, the influence of the ratio of Al2O3/ZrO2 in slurries on the properties of Al2O3-ZrO2 RPCs are investigated, also the residual stress within the Al2O3-ZrO2 multi-layered struts is systematically explored. The results show that the Al2O3-ZrO2 slurry with 0.2 wt% FS20, 0.3 wt% PVA and 0.6 wt% CMC exhibits excellent rheological behavior. In addition, based on the results of finite element method and experiments, as the RPCs with a large amount of Al2O3 in outer layer the compressive residual stress (tangential direction) will exist in the outer layer and reduce the thermal stress concentration near the surface and the edge of struts, which are beneficial to improve the properties of RPCs.