Specifies a test method that covers the determination of fracture resistance of silicon nitride bearing balls at room temperature by the indentation fracture (IF) method, as specified in ISO 26602.

This International Standard describes a test method that covers the determination of fracture resistance of silicon nitride bearing balls at room temperature by the indentation fracture (IF) method, as specified in ISO26602.

This International Standard is intended for use with monolithic silicon nitride ceramics for bearing balls. It does not include other ceramic materials.

This International Standard is for material comparison and quality assurance.

Indentation fracture resistance, K_{I, IFR} as defined in this International Standard is not to be equated to fracture toughness determined using other test methods such as K_Isc and K_Ipb.

NOTE K_{I, 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 used for silicon nitride materials since these properties are governed by the resistance to crack extension in localized damage areas. By contrast, fracture toughness, K_Isc and K_Ipb 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.