Fracture behavior of directionally solidified CeO2- and Pr2O3-doped Y3Al5O12/Al2O3 eutectic composites

The microstructural features and fracture behavior of CeO2- and Pr2O3-doped Y3Al5O12/Al2O3 eutectic composites grown by an edge-defined film-fed growth (EFG) technique were studied. The microstructures of the composites were examined using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Fracture toughness and crack propagation behavior of the composites were investigated using an indentation technique. The fracture toughness (K1C) of CeO2- and Pr2O3-doped Y3Al5O12/Al2O3 eutectic composites were measured to be 4.99 MPa m1/2 and 2.79 MPa m1/2, respectively. Crack deflection was observed occasionally in both CeO2- and Pr2O3-doped Y3Al5O12/Al2O3 eutectic composites.