EN ISO 24370:2023 PDF

Overview

EN ISO 24370:2023 (identical to ISO 24370:2005) specifies a standardized test method for fracture toughness of monolithic and macroscopically homogeneous whisker- or particulate-reinforced ceramics at room temperature using the chevron-notched beam (CNB) method. Adopted by CEN in 2023, this standard is intended for material development, comparison, quality assurance and generation of design data for fine ceramics and advanced technical ceramics.

Key topics and technical requirements

• Test principle: Four-point flexure of a beam specimen containing a chevron-shaped notch; stable crack extension is induced and fracture toughness (K_I,CNB) is calculated from the fracture load and a minimum stress intensity factor coefficient Y*.
• Scope limits: Applicable to monolithic ceramics and whisker/particulate-reinforced ceramics considered macroscopically homogeneous. Not applicable to continuous-fibre reinforced ceramic composites.
• Material range: Usually applicable to materials with fracture toughness less than about 12 MPa·√m and suitable for materials with a flat R-curve; may be used for some rising R-curve materials.
• Specimen and fixture: Geometry, notch dimensions and edge chamfering are specified to ensure stable crack growth. Notch width should be narrow (typically