Measurement of the dynamic fracture toughness of alumina ceramic

Abstract

In this study, the dynamic fracture toughness of the alumina ceramic at various loading rates was measured by using three test methods. A split Hopkinson pressure bar was used to apply dynamic loading. The three-point bending (TPB) test with a pre-crack and semi-circular bending (SCB) test with a pre-crack, and the flattened Brazilian disc (FBD) test without a pre-crack were used to measure the dynamic fracture toughness of alumina  ceramic. The dynamic fracture toughness of alumina ceramic obtained by the three methods were compared and analyzed. The results by the three methods show a good consistency. The dynamic fracture toughness of alumina ceramic exhibits an obvious rate dependence upon the loading rate. Considering easy preparation of FBD specimens without fabricating a pre-crack, FBD test is recommended as an alternative method for measuring the dynamic fracture toughness of brittle materials.