What is BS EN 820-5 - Elastic moduli of monolithic ceramics about?
BS EN 820-5 focuses on advanced technical ceramics. BS EN 820-5 is the fifth part of the thermal features of the monolithic ceramics series that describes methods for determining the elastic moduli.
BS EN 820-5 describes Young's modulus, shear modulus and Poisson's ratio, of advanced monolithic technical ceramics at temperatures above room temperature.
Note 1: Method C in EN 843-2 based on ultrasonic time of flight measurement has not been incorporated into this part of EN 820. Although the method is feasible to apply, it is specialized, and outside the capabilities of most laboratories. There are also severe restrictions on test piece geometries and methods of achieving pulse transmission. For these reasons, this method has not been included in EN 820-5.
Note 2: The upper-temperature limit for this test depends on the properties of the test pieces and can be limited by softening within the timescale of the test. In addition, for method A there can be limits defined by the choice of test jig construction materials.
Note 3: Methods B and C may not be appropriate for materials with significant levels of porosity which causes damping and an inability to detect resonances or natural frequencies, respectively.
Note 4: This method does not provide for the effects of thermal expansion, i.e., the measurements are based on room temperature dimensions.
Note 5: All the test methods assume the use of homogeneous test pieces of linear elastic materials. The test assumes that the test piece has isotropic elastic properties. At high porosity levels, all of the methods can become inappropriate. The maximum grain size (see EN 623-3), excluding deliberately added whiskers, should be less than 10 % of the minimum dimension of the test piece.
Who is BS EN 820-5 - Elastic moduli of monolithic ceramics for?
BS EN 820-5 on Thermal features of ceramics is useful for:
- Monolithic ceramics manufacturers
- Testing laboratories
- Aerospace Engineers
- Aircraft Manufacturers
Why should you use BS EN 820-5 - Elastic moduli of monolithic ceramics?
Monolithic ceramics have various thermomechanical features that make them highly useful in important applications. These important applications include aerospace applications too. Their durability, elastic modulus resistance to high temperatures and high credibility have made them high in demand. Elastic moduli is the unit of measurement of an object's or substance's resistance to being deformed elastically (i.e., non-permanently) when a stress is applied to it. This is a powerful feature as it depicts the stiffness of the ceramics.
- BS EN 820-5 demonstrates three alternative methods : The determination of young's modulus by static flexure of a thin beam in three- or four-point bending.
- The determination of young's modulus by forced longitudinal resonance, or young's modulus, shear modulus and poisson's ratio by forced flexural and torsional resonance, of a thin beam.
- The determination of Young's modulus from the fundamental natural frequency of a struck bar (impulse excitation method).
Determining elastic moduli will help in concluding how much the ceramics can stretch which can be a highly useful feature in its critical application. Hence, using BS EN 820-5 can ensure the reliability of ceramics.
