EN ISO 18756:2005 PDF

Scope: This International Standard specifies a test method for determining the fracture toughness of monolithic ceramic materials, carried out at room temperature on bending specimens with a surface crack (Knoop crack) (SCF method). This International Standard is intended for application to monolithic ceramics and whisker-reinforced ceramics that are considered macroscopically homogeneous. Ceramic composites with continuous fiber reinforcement are not covered. The test method is applicable to ceramic materials with flat or rising crack resistance curves (R-curves). It is similar to the method specified in ISO 15732, but the cracks are smaller and are created in a different way. Both methods should produce similar or identical results for materials with a flat crack resistance curve. NOTE The test method specified in this standard is generally applicable to ceramic materials that have a fracture toughness of less than 10 MPa m1/2. In materials with greater fracture toughness or in particularly soft ceramic materials (with low hardness), e.g. B. some zirconium oxides, or even in porous ceramic materials, it can be difficult to create cracks with a Knoop indenter.

EN ISO 18756:2005 Referenced Document

ISO 14704:2000 Fine ceramics (advanced ceramics, advanced technical ceramics) - Test method for flexural strength of monolithic ceramics at room temperature
ISO 3611:1978 Micrometer callipers for external measurement
ISO 7500-1:2004 Metallic materials - Verification of static uniaxial testing machines - Part 1: Tension/compression testing machines - Verification and calibration of the force-measuring system

2005 EN ISO 18756:2005 Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of fracture toughness of monolithic ceramics at room temperature by the surface crack in flexure (SCF) method