BS ISO 14704:2015 pdf download – Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for flexural strength of monolithic ceramics at room temperature 1 Scope This International Standard specifies a test method for determining the flexural strength of monolithic fine ceramics, and whisker- or particulate-reinforced ceramic composites, at room temperature and applies to materials with grain size less than 200 µm. This test method may be used for materials development, quality control, characterization and design data-generation purposes. NOTE Since fracture is due to tensile stress, flexural strength data can be used to calculate a uniaxial tensile strength considering the effect of the tested volume and Weibull-statistics. So, flexural strength is often used in substitute for uniaxial tensile strength. 2 Normative references The following referenced documents are indispensable for the application 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 361 1 :1 978, 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 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 flexural strength maximum nominal stress at fracture of a specified elastic beam loaded in bending 3.2 four-point flexure configuration of flexural strength testing where a specimen is loaded equally by two bearings symmetrically located between two support bearings See Figure 1 a) and b). NOTE The bearings may be cylindrical rollers or cylindrical bearings. 4 Principle A beam specimen with a rectangular cross-section is loaded in flexure until fracture. The load at fracture, the test fixture and specimen dimensions are used to compute the flexural strength which is often used in substitute for uniaxial tensile strength of a ceramic. The material is assumed to be isotropic and linearly elastic. 5 Apparatus 5.1 Testing machine The testing machine shall be capable of applying a force to the loading roller (three-point flexure) or equally to the loading rollers (four-point flexure) in order to stress the specimen. The machine shall be capable of applying the force at a constant loading or displacement rate. The test machine shall be equipped for recording the peak load applied to the specimen. The accuracy of the test machine shall be in accordance with ISO 7500-1 :2004, Class 1 , with an accuracy of 1 % of indicated load...
Download Address
Download