Comparison of fracture toughness measuring methods applied on silicon nitride ceramics

Abstract:. Different fracture toughness testing methods on unreinforced and with Si3N4 whiskers reinforced silicon nitride ceramics were compared. The results revealed that in the reinforced ceramics the KIC rises with the increasing of the crack size, which indicates a rising R-curve behaviour in this system. Using IF testing method equations given by Niihara and by Shetty proved to have the nearest values to these achieved using SENB in both investigated systems. 1