Strong and tough laminated ceramics prepared from ceramic foams

Here, we present a novel strategy to prepare laminated ceramics by combining the ceramic foams and hot-pressing sintering. Al2O3 and ZrO2 ceramic foams prepared by the particle-stabilized foaming method was cut into thin slices and then directly laminated and hot-pressing sintered. Al2O3/ZrO2 laminated ceramics with various structures were prepared. Compared with the slices prepared by conventional process, ceramic foams can easily regulate the thickness of laminate to resemble the nacre-like structure. In addition, the grain in the ceramic foams have lower activity and shrinkage rate, thereby weakening the residual tensile internal stress caused by grain coarsening and differences in coefficient of thermal expansion. The effects of layer number and thickness ratio on residual stress and the structure-activity relationship between mechanical properties and microstructure were investigated. The fracture toughness, flexural strength, and work of fracture of the optimal Al2O3/ZrO2 laminated ceramics are 8.2 +/- 1.3 MPa center dot m(1/2), 356 +/- 59 MPa, and 216 J center dot m(-2), respectively.

Automated summary

In this study, a new strategy to prepare laminated ceramics by combining ceramic foams and hot-pressing sintering is presented. Al2O3 and ZrO2 ceramic foams prepared by the particle-stabilized foaming method were cut into thin slices and directly laminated and hot-pressing sintered. Al2O3/ZrO2 laminated ceramics with various structures were successfully prepared. The use of ceramic foams allows for easy regulation of the laminate thickness to resemble the nacre-like structure and reduces residual tensile internal stress caused by grain coarsening and differences in coefficient of thermal expansion. The optimal Al2O3/ZrO2 laminated ceramics exhibited excellent fracture toughness, flexural strength, and work of fracture.