Fabrication and mechanical properties of Al2O3/SiC/ZrO2 functionally graded material by electrophoretic deposition

This study describes the synthesis of Al2O3/SiC/ZrO2 functionally graded material (FGM) in bio-implants (artificial joints) by electrophoretic deposition (EPD). A suitable suspension that was based on 2-butanone was applied for the EPD of Al2O3/SiC/ZrO2, and a pressureless sintering process was applied as a presintering. Hot isostatic pressing (HIP) was used to densify the deposit, with beneficial mechanical properties after 2 h at 1800 degrees C in Ar atmosphere. The maximum hardness in the outer layer (90 vol. Al2O3 + 10 vol. SiC) and maximum fracture toughness in the core layer (75 vol. Al2O3 + 10 vol. SiC + 15 vol. ZrO2) composite were 20.8 +/- 0.3 GPa and 8 +/- 0.1 MPa m(1/2), respectively. The results, when compared with results from Al2O3/ZrO2 FGM, showed that SiC increased the compressive stresses in the outer layers, while the inner layers were under a residual tensile stress. (C) 2012 Elsevier Ltd. All rights reserved