DIN EN 820-5-2009 Advanced technical ceramics - Thermomechanical properties of monolithic ceramics - Part 5 Determination of elastic moduli at elevated temperatures English version.pdf

1、October 2009DEUTSCHE NORM English price group 13No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 81.060.30!$Y“1549658ww

2、w.din.deDDIN EN 820-5Advanced technical ceramics Thermomechanical properties of monolithic ceramics Part 5: Determination of elastic moduli at elevated temperaturesEnglish version of DIN EN 820-5:2009-10Hochleistungskeramik Thermomechanische Eigenschaften monolithischer Keramik Teil 5: Bestimmung de

3、r elastischen Moduln bei erhhten TemperaturenEnglische Fassung DIN EN 820-5:2009-10SupersedesDIN CEN/TS 820-5:2004-04www.beuth.deDocument comprises pages27DIN EN 820-5:2009-10 National foreword This standard has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics” (Secretari

4、at: BSI, United Kingdom). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Technical Committee NA 062-02-91 AA Prfung von Hoch-leistungskeramik Monolithische Werkstoffe. The DIN Standards corresponding to the Inte

5、rnational Standards referred to in the EN ISO are as follows: ISO 463 DIN EN ISO 463 ISO 3611 DIN 863-1 Amendments This standard differs from DIN CEN/TS 820-5:2004-04 as follows: a) The standard has been editorially revised. Previous editions DIN CEN/TS 820-5: 2004-04 National Annex NA (informative)

6、 Bibliography DIN 863-1, Verification of geometrical parameters Micrometers Part 1: Standard design micrometer callipers for external measurement; concepts, requirements, testing DIN EN ISO 463, Geometrical Product Specifications (GPS) Dimensional measuring equipment Design and metrological characte

7、ristics of mechanical dial gauges 2 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 820-5 July 2009 ICS 81.060.30 Supersedes CEN/TS 820-5:2004 English Version Advanced technical ceramics Thermomechanical properties of monolithic ceramics Part 5: Determination of elastic moduli at elevated tempe

8、raturesCramiques techniques avances Proprits thermomcaniques des cramiques monolithiques Partie 5: Dtermination des modules lastiques temprature leves Hochleistungskeramik Thermomechanische Eigenschaften monolithischer Keramik Teil 5: Bestimmung der elastischen Moduln bei erhhten Temperaturen This E

9、uropean Standard was approved by CEN on 12 June 2009. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references co

10、ncerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its

11、own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithu

12、ania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 C

13、EN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 820-5:2009: EEN 820-5:2009 (E) 2 Contents Page Foreword . 31 Scope 42 Normative references . 43 Terms and definitions . 54 Method A: Static bending method . 54.1 Principle . 54.2 Appar

14、atus 54.3 Test pieces . 94.4 Procedure 94.5 Calculation of results 94.6 Accuracy and interferences . 115 Method B: Resonance method 125.1 Principle . 125.2 Apparatus 125.3 Test pieces . 155.4 Procedure 155.5 Calculation of results 165.6 Accuracy and interferences . 186 Method C: Impulse excitation m

15、ethod 186.1 Principle . 186.2 Apparatus 186.3 Test pieces . 216.4 Procedure 216.5 Calculation . 216.6 Accuracy and interferences . 227 Test report . 227.1 General . 227.2 Method A 237.3 Method B 237.4 Method C 24Bibliography . 25DIN EN 820-5:2009-10 EN 820-5:2009 (E) 3 Foreword This document (EN 820

16、-5:2009) has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics”, the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2010, a

17、nd conflicting national standards shall be withdrawn at the latest by January 2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. Th

18、is document supersedes CEN/TS 820-5:2004. EN 820 consists of five parts, under the general title “Advanced technical ceramics - Methods of testing monolithic ceramics - Thermomechanical properties“: Part 1: Determination of flexural strength at elevated temperatures Part 2: Determination of self-loa

19、ded deformation Part 3: Determination of resistance to thermal shock by water quenching Part 4: Determination of flexural creep deformation at elevated temperatures Part 5: Determination of elastic moduli at elevated temperatures According to the CEN/CENELEC Internal Regulations, the national standa

20、rds organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Por

21、tugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 820-5:2009-10 EN 820-5:2009 (E) 4 1 Scope This part of EN 820 describes methods for determining the elastic moduli, specifically Youngs modulus, shear modulus and Poissons ratio, of advanced monolithic tech

22、nical ceramics at temperatures above room temperature. The standard prescribes three alternative methods for determining some or all of these three parameters: A the determination of Youngs modulus by static flexure of a thin beam in three- or four-point bending. B the determination of Youngs modulu

23、s by forced longitudinal resonance, or Youngs modulus, shear modulus and Poissons ratio by forced flexural and torsional resonance, of a thin beam. C the determination of Youngs modulus from the fundamental natural frequency of a struck bar (impulse excitation method). This part of EN 820 extends th

24、e above-defined room-temperature methods described in EN 843-2 to elevated temperatures. 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 b

25、ecome 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. 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. Altho

26、ugh the method is feasible to apply, it is specialised, 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 temper

27、ature 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 material

28、s with significant levels of porosity (i.e. 15 %) which cause 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. Depending upon t

29、he use to which the data are put, it can be necessary to make a further correction by multiplying each dimensional factor in the relevant equations by a factor (1 + T) where is the mean linear expansion coefficient over the temperature interval T from room temperature. 2 Normative references The fol

30、lowing 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. EN 820-1, Advanced technical ceramics Method of testing

31、monolithic ceramics Thermo-mechanical properties Part 1: Determination of flexural strength at elevated temperatures EN 843-1:2006, Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature Part 1: Determination of flexural strength EN 60584-2, Thermocouples Part 2

32、: Tolerances (IEC 60584-2:1982 + A1:1989) EN ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system (ISO 7500-1:2004) DIN EN 820-5:2009-10 EN 820-5:2009 (E) 5 EN ISO/IEC 1

33、7025, General requirements for the competence of testing and calibration laboratories (ISO/IEC 17025:2005) ISO 463, Geometrical Product Specifications (GPS) Dimensional measuring equipment Design and metrological characteristics of mechanical dial gauges ISO 3611, Micrometer callipers for external m

34、easurement ISO 6906, Vernier callipers reading to 0,02 mm 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 Youngs modulus stress required in a material to produce unit strain in uniaxial extension or compression 3.2 shear modulus shear stress

35、required in a material to produce unit angular distortion 3.3 Poissons ratio negative value of the ratio of lateral strain to longitudinal strain in an elastic body stressed longitudinally 3.4 static elastic moduli elastic moduli determined in an isothermal condition by stressing statically or quasi

36、statically 3.5 dynamic elastic moduli elastic moduli determined non-quasistatically, i.e. under adiabatic conditions, such as in the resonant, ultrasonic pulse or impulse excitation methods 4 Method A: Static bending method 4.1 Principle Using three- or four-point bending of a thin beam test piece,

37、the elastic distortion is measured, from which Youngs modulus may be calculated according to thin beam equations. 4.2 Apparatus 4.2.1 Test jig, in accordance with that described in EN 820-1 for flexural strength testing at elevated temperatures in terms of its function, i.e. the support and loading

38、rollers shall be free to roll, and to articulate to ensure axial and even loading as described in EN 843-1. The test jig shall be made of materials which do not interact with the test piece and which remain essentially elastic at the maximum test temperature. A typical arrangement is shown in Figure

39、 1. NOTE 1 Articulation is not essential for carefully machined flat and parallel-faced test pieces. The outer span of the test jig shall be 40 mm or greater. DIN EN 820-5:2009-10 EN 820-5:2009 (E) 6 NOTE 2 If the displacement is to be measured by method 1 (see 4.2.5), a span of up to 100 mm, or a s

40、pan to thickness ratio in excess of 20, is recommended to obtain large displacements and to ensure that the compliance of the machine is a small correction if displacement is recorded as a machine cross-head movement. The test jig may be either for three-point or four-point flexure. The latter metho

41、d is required if displacement is determined by differential transducer. 4.2.2 Mechanical testing machine, capable of applying a force to the test jig at a constant displacement rate. The test machine shall be equipped for recording the load applied to the test jig at any point in time. The accuracy

42、of the test machine shall be in accordance with EN ISO 7500-1, Grade 1 (1 % of indicated load), and shall be capable of recording to a sensitivity of better than 0,1 % of the maximum load employed. 4.2.3 Thermal enclosure and control system, surrounding the test piece, capable of achieving the maxim

43、um desired temperature and maintaining it to 2 C for test temperatures up to 1 000 C, and 4 C at higher temperatures. NOTE The system can operate with an air or inert atmosphere, or with a vacuum inside the thermal enclosure. Especially with regard to use in vacuum, efforts should be made to ensure

44、that the force applied at the test piece is correctly recorded by the load cell outside the enclosure, taking account of friction or elastic resistances in seals or bellows systems. 4.2.4 Thermocouple, conforming to EN 60584-2 for measuring the test piece temperature. The thermocouple shall be in cl

45、ose proximity to but shall not touch the test piece. 4.2.5 Displacement measuring device, for recording the displacement of the loaded test piece by one of two methods: Method 1 Recording the apparent displacements of the test machine as the test piece is loaded in the test jig, and again with the t

46、est piece replaced by a ceramic bar at least 15 mm thick with flat and parallel faces to within 0,05 mm. The difference between these displacements is equivalent to the displacement of the test piece in the test jig. The displacement recording device (chart recorder, digital indicator, etc.) shall b

47、e calibrated by comparing machine cross-head displacement with the movement indicated on a dial gauge contacting the cross-head, or other suitable calibrated displacement measuring device. The dial gauge shall be in accordance with ISO 463, or the alternative device otherwise certified as accurate t

48、o 0,01 mm. The parts of the load train subjected to elevated temperatures shall be made of materials which remain elastic at the maximum test temperature. Method 2 Recording the displacement of the test piece directly using a transducer extensometer contacting at least two defined points on the surf

49、ace of the test piece between the support loading rollers in three-point or four-point bending. The defined points shall preferably be: for four-point bending: the centre of the span and one or both loading rollers (see for example Figure 1, right); for three-point bending: the centre of the span and one or both support rollers (see for example Figure 1, left). N