NBN ISO 21618:2021

This document describes a test method that covers the determination of fracture resistance of
monolithic ceramics at room temperature by the indentation fracture (IF) method.
This document is intended for use with dense monolithic ceramics and whisker- or particulate-
reinforced ceramics which are regarded as macroscopically homogeneous. It does not include monolithic
silicon nitride ceramics for bearing balls and continuous-fibre-reinforced ceramics composites.
This document is for material development, material comparison, quality assurance, characterization
and reliability data generation.
Indentation fracture resistance, KI,IFR, as defined in this document is not to be equated with fracture
toughness determined using other test methods such as KIsc and KIpb
.
NOTE KI,IFR is an estimate of a material’s resistance to cracking as introduced by an indenter and has
correlations with wear resistance and rolling contact fatigue performance as well as machining processes, since
these properties are governed by the resistance to crack extension in localized damage areas[1]-[3]. By contrast,
fracture toughness properties KIsc and KIpb
are intrinsic properties of a material and are relevant to macroscopic
and catastrophic fracture events with long cracks rather than those phenomena caused by microscopic and
successive damage accumulation associated with short cracks.