Breviary Technical Ceramics






10.5 Measurement Procedures

10.5.1 Bending Strength

The fracture strength measured during a bending test depends on many factors such as the dimensions, cross sectional geometry, surface quality, loading velocity, environmental humidity, the geometry of the test device and the procedure. The result of such a test gives an indication of the general magnitude of the strength properties of the material, but cannot be directly used as design data. It is suitable for quality-control and for the general comparison with various materials, provided all of the parameters mentioned above remain constant. In practice, both 3-point and 4-point bending tests are used.

The necessary test equipment consists of:

  • a mechanical test machine, with which a test piece is loaded with constant rate of force increase and which is capable of measuring the peak stress with an accuracy of ± 1 %,
  • a test piece loading jig whose geometry and dimensions are suitable for the test,
  • a micrometer meeting the specifications of ISO 3 611 and capable of measuring test piece dimensions to an accuracy of ± 0.01 mm,
  • a travelling microscope with a slide rule or similar measuring device meeting the specifications of ISO 6 906 in order to measure the distance between the centre axes of the sample supports and the loading pins.


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