Damage resistance and R-curve behavior of multilayer Al2O3/SiC ceramics

Damage resistance and R-curve behavior of multilayer Al2O3/SiC ceramics were evaluated in bending by the indentation-strength and the single-edge-notched-beam methods. Due to the crack deflection at the Al2O3/SiC interfaces, a plateau indentation strength response was achieved, suggesting an exceptional resistance to contact-induced damage. Moreover, fracture toughness was observed to increase from 8.0 to 15.5 MPa m1/2 with increasing notch depth from 0.5 to 2.0 mm, indicative of a strong R-curve behavior.