ISO 21712:2020 pdf download

ISO 21712:2020 pdf download.Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for flexural bond strength of ceramics
1 Scope
This document specifies a test method for determining the flexural bond strength of ceramic/ceramic joints or ceramic/metal joints at room temperature. The substrate materials, for example ceramic or metal, are both monolithic. This method can be used to test the interfacial bond strength of the joint under bending conditions. It can be used for the development of joining materials and/or for the quality control of joints, the characterization and generating design data purposes.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3611, Geometrical product specifications (GPS) — Dimensional measuring equipment: Micrometers for external measurements — Design and metrological characteristics
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 14704:2016, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for flexural strength of monolithic ceramics at room temperature
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 flexural bond strength
maximum stress at fracture at the bond interface of a specified beam containing the ceramic/ceramic joint or the ceramic/metal joint subjected to bending
3.2 four-point flexure
configuration of flexural test where a specimen is subjected to equal loads through two bearings symmetrically located between two support bearings
Note 1 to entry: See Figure 1 a) and b).
Note 2 to entry: The bearings may be cylindrical rollers or cylindrical bearings.
4 Principle
A beam-type specimen containing the specific bond joint with a rectangular cross-section or circular cross-section is loaded in flexure until fracture. The load at fracture, the geometry of the test fixture and specimen dimensions are used to compute the flexural bond strength, which is a measure of the bond strength. The material or joining interface is assumed to be linearly elastic.
5.1 Testing machine
A suitable testing machine capable of applying a uniform crosshead speed shall be used. The testing machine shall have the function for recording the peak load applied to the test specimen. The testing machine shall fulfil the requirements of ISO 7500-1, Class 1, with an accuracy of 1 % of the indicated load at fracture.