1、BRITISH STANDARDBS EN 843-2:2006Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature Part 2: Determination of Youngs modulus, shear modulus and Poissons ratioThe European Standard EN 843-2:2006 has the status of a British StandardICS 81.060.30g49g50g3g38g50g51
2、g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 843-2:2006This British Standard was published under the authority of the Standards Policy and Strategy Committe
3、e on 31 January 2007 BSI 2007ISBN 978 0 580 49981 4National forewordThis British Standard was published by BSI. It is the UK implementation of EN 843-2:2006. It supersedes DD ENV 843-2:1996 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanc
4、ed technical ceramics.A list of organizations represented on RPI/13 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer
5、immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 843-2December 2006ICS 81.060.30 Supersedes ENV 843-2:1995 English VersionAdvanced technical ceramics - Mechanical properties ofmonolithic ceramics at room temper
6、ature - Part 2: Determinationof Youngs modulus, shear modulus and Poissons ratioCramiques techniques avances - Proprits mcaniquesdes cramiques monolithiques temprature ambiante -Partie 2: Dtermination du module dYoung, du module decisaillement et du coefficient de PoissonHochleistungskeramik - Mecha
7、nische Eigenschaftenmonolithischer Keramik bei Raumtemperatur - Teil 2:Bestimmung des Elastizittsmoduls, Schubmoduls und derPoissonzahlThis European Standard was approved by CEN on 11 November 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditio
8、ns for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three offici
9、al versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgi
10、um, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATI
11、ONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 843-2:2006: EEN 843-2:2006 (E) 2 Contents Page Foreword4 1 Scop
12、e 5 2 Normative references 5 3 Terms and definitions .6 4 Method A: Static flexure method6 4.1 Principle6 4.2 Apparatus .7 4.3 Test pieces .8 4.4 Procedure .8 4.5 Calculations11 4.6 Measurement uncertainty .13 5 Method B: Resonance method.13 5.1 Principle13 5.2 Apparatus .13 5.3 Test pieces .14 5.4
13、Procedure .16 5.5 Calculations18 5.6 Measurement uncertainty .20 6 Method C: Ultrasonic method.20 6.1 Principle20 6.2 Apparatus .20 6.3 Test pieces .22 6.4 Test method22 6.5 Calculations23 6.6 Measurement uncertainty .23 7 Method D: Impulse excitation method.24 7.1 Principle24 7.2 Apparatus .24 7.3
14、Test pieces .24 7.4 Procedure .24 7.5 Calculations27 7.6 Measurement uncertainty .27 8 Report .28 8.1 General28 8.2 Method A.28 8.3 Method B.28 8.4 Method C.29 8.5 Method D.29 Annex A (informative) Impact excitation method applied to disc test pieces.30 A.1 Scope 30 A.2 Apparatus .30 A.3 Test pieces
15、 .30 A.4 Principle30 A.5 Method 31 A.6 Calculations32 A.7 Interferences 32 A.8 Measurement uncertainty .33 EN 843-2:2006 (E) 3 A.9 Report .33 Annex B (informative) Round-robin validation of test methods 37 B.1 Objectives 37 B.2 Materials .37 B.3 Test facilities37 B.4 Results37 B.5 Conclusions .38 Bi
16、bliography39 EN 843-2:2006 (E) 4 Foreword This document (EN 843-2:2006) 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 ide
17、ntical text or by endorsement, at the latest by June 2007, and conflicting national standards shall be withdrawn at the latest by June 2007. This document supersedes ENV 843-2:1995. EN 843 Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature comprises six part
18、s: Part 1: Determination of flexural strength Part 2: Determination of Youngs modulus, shear modulus and Poissons ratio Part 3: Determination of subcritical crack growth parameters from constant stressing rate flexural strength tests Part 4: Vickers, Knoop and Rockwell superficial hardness Part 5: S
19、tatistical analysis Part 6: Guidance for fractographic investigation At the time of publication of this Revision of Part 2, Part 6 was available as a Technical Specification. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound
20、to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland an
21、d United Kingdom. EN 843-2:2006 (E) 5 1 Scope This part of EN 843 specifies methods for determining the elastic moduli, specifically Youngs modulus, shear modulus and Poissons ratio, of advanced monolithic technical ceramics at room temperature. This European Standard prescribes four alternative met
22、hods 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 flexure. B The determination of Youngs modulus by forced longitudinal resonance, or Youngs modulus, shear modulus and Poissons ratio by forced fl
23、exural and torsional resonance, of a thin beam. C The determination of Youngs modulus, shear modulus and Poissons ratio from the time-of-flight of an ultrasonic pulse. D The determination of Youngs modulus from the fundamental natural frequency of a struck bar (impulse excitation method). All the te
24、st methods assume the use of homogeneous test pieces of linear elastic materials. NOTE 1 Not all ceramic materials are equally and linearly elastic in tension and compression, such as some porous materials and some piezoelectric materials. With the exception of Method C, the test assumes that the te
25、st piece has isotropic elastic properties. Method C may be used to determine the degree of anisotropy by testing in different orientations. NOTE 2 An ultrasonic method for dealing with anisotropic materials (ceramic matrix composites) can be found in ENV 14186 1. An alternative to Method D for isotr
26、opic materials using disc test pieces is given in Annex A. NOTE 3 At high porosity levels all of the methods except Method C may become inappropriate. The methods are only suitable for a maximum grain size (see EN 623-3), excluding deliberately added whiskers, of less than 10 % of the minimum dimens
27、ion of the test piece. NOTE 4 The different methods given in this European Standard can produce slightly different results on the same material owing to differences between quasi-isothermal quasi-static and quasi-adiabatic dynamic conditions. In addition, the calculation routines for different metho
28、ds have different origins and different potential uncertainties which have not been rigorously evaluated in producing this European Standard. Some information is given in Annex B (see also reference 2). 2 Normative references The following referenced documents are indispensable for the application o
29、f 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 623-2, Advanced technical ceramics Monolithic ceramics General and textural properties Part 2: Determination of density
30、and porosity EN 623-3, Advanced technical ceramics Monolithic ceramics General and textural properties Part 3: Determination of grain size and size distribution (characterized by the Linear Intercept Method) EN 623-4, Advanced technical ceramics Monolithic ceramics General and textural properties Pa
31、rt 4: Determination of surface roughness EN 843-2:2006 (E) 6 EN 843-1:2006, Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature Part 1: Determination of flexural strength EN ISO 463, Geometrical Product Specifications (GPS) Dimensional measuring equipment Des
32、ign and metrological characteristics of mechanical dial gauges (ISO 463:2006) 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) EN ISO/IEC 17025,
33、 General requirements for the competence of testing and calibration laboratories (ISO/IEC 17025:2005) ISO 3611, Micrometer callipers for external measurement ISO 6906, Vernier callipers reading to 0,02 mm 3 Terms and definitions For the purposes of this document, the terms and definitions given in E
34、N 843-1:2006 and the following 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 required in a material to produce unit angular distortion 3.3 Poissons ratio negative value of the ratio of lateral strain
35、 to longitudinal strain in an elastic body stressed longitudinally 3.4 static elastic moduli elastic moduli determined in a quasi-isothermal condition by stressing statically or quasistatically 3.5 dynamic elastic moduli elastic moduli determined non-quasistatically, i.e. under quasi-adiabatic condi
36、tions, such as in the resonant, ultrasonic pulse or impulse excitation methods 4 Method A: Static flexure method 4.1 Principle Using three- or four-point flexure of a thin beam test piece, the elastic distortion is measured, from which Youngs modulus may be calculated according to thin-beam equation
37、s. EN 843-2:2006 (E) 7 4.2 Apparatus 4.2.1 Test jig capable of three-point or four-point flexure. The test jig shall be in accordance with that described in EN 843-1 in terms of its function, i.e. the support and loading rollers shall be free to roll, and to articulate to ensure axial and even loadi
38、ng. 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. NOTE 2 If the availability of test material allows, a span of at least 100 mm is recommended to obtain large displacements and to ensure that
39、 the compliance of the machine is a small correction if displacement is recorded as a machine cross-head movement. The test jig shall be for four-point flexure, if displacement is determined by strain gauges or differential transducer. 4.2.2 Test machine capable of applying a force to the test jig a
40、t 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 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 0
41、,1 % of the maximum load employed. The calibration shall have been checked within the previous year. 4.2.3 Displacement or strain measuring device 4.2.3.1 General Equipment shall be installed to measure the displacement or strain of the loaded test piece by one of three methods, in accordance with 4
42、.2.3.2, 4.2.3.3 or 4.2.3.4. 4.2.3.2 Method A.1 A facility is designed to measure the apparent displacements of the test machine with the test piece (Figure 1 a), and with the test piece replaced by a steel or ceramic bar at least 15 mm thick. The difference between these displacements is equivalent
43、to the displacement of the test piece in the test jig. The displacement recording device shall be calibrated by comparing machine cross-head displacement with the movement indicated on a dial gauge or other displacement measuring device (see 4.2.5) contacting the cross-head. 4.2.3.3 Method A.2 A fac
44、ility is designed to measure the displacement of the test piece directly using transducers contacting two defined points on the surface of the test piece between the support loading rollers in three-point or four-point bending (Figure 1 b). The defined points shall be the centre of the span and one
45、or both loading rollers in four-point bending, or the centre of the span and one or both support rollers in three-point bending. The transducer shall be capable of detecting movements with an accuracy of 0,001 mm, shall have output linear to 0,01 % and shall be calibrated to an accuracy of 0,1 %. 4.
46、2.3.4 Method A.3 A facility is designed to record the strain on the surface of the test piece by using a strain gauge placed on the surface of the test piece between the central loading rollers in four-point bending (Figure 1 c). The strain gauge and its associated bridge circuit shall have an accur
47、acy of better than 0,1 % and shall be capable of resolving a strain of less than 10-5. EN 843-2:2006 (E) 8 NOTE It is recommended that the strain gauge should only be applied by experienced personnel in order to ensure it performs accurately. It is also recommended that two or more gauges are fitted
48、 and their outputs recorded simultaneously in order to provide a check on reproducibility. 4.2.4 Micrometer in accordance with ISO 3611, but capable of recording to 0,002 mm, or other device of equivalent accuracy, for measuring the dimensions of the test piece. 4.2.5 Dial gauge in accordance with E
49、N ISO 463 or other calibrated displacement measuring device, capable of recording to 0,01 mm. 4.3 Test pieces Test pieces shall be rectangular section bars selected and prepared by agreement between parties. They may be directly prepared close to final dimensions or machined from larger blocks. This test measures Youngs modulus parallel to the length of the test piece. If the test material is likely to be elastically anisotropic, care shall be taken in selection of the test piece orientation and in the int
