UNE-EN ISO 14627:2025

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 ISO 26602.

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, KI, IFR as defined in this International Standard is not to be equated to 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 used for silicon nitride materials

since these properties are governed by the resistance to crack extension in localized damage areas. By contrast, fracture

toughness, 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.