BS EN 1894-2005 Advanced technical ceramics - Mechanical properties of ceramic composites at high temperature under inert atmosphere - Determination of shear strength by compressio.pdf

1、BRITISH STANDARD BS EN 1894:2005 Advanced technical ceramics Mechanical properties of ceramic composites at high temperature under inert atmosphere Determination of shear strength by compression loading of notched specimens The European Standard EN 1894:2005 has the status of a British Standard ICS

2、81.060.30 BS EN 1894:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 6 May 2005 BSI 6 May 2005 ISBN 0 580 45998 5 National foreword This British Standard is the official English language version of EN 1894:2005. It supersedes DD ENV 1894

3、:1996 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanced technical ceramics, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British

4、 Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online

5、. 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 does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible

6、 international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, th

7、e EN title page, pages 2 to 11 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1894 April 2005 ICS 81.060.30 Supersedes E

8、NV 1894:1996 English version Advanced technical ceramics - Mechanical properties of ceramic composites at high temperature under inert atmosphere - Determination of shear strength by compression loading of notched specimens Cramiques techniques avances - Proprits mcaniques des cramiques composites h

9、aute temprature sous atmosphre neutre - Dtermination de la rsistance au cisaillement par compression dprouvettes entailles Hochleistungskeramik - Mechanische Eigenschaften von keramischen Verbundwerkstoffen bei hoher Temperatur in inerter Atmosphre - Bestimmung der Scherfestigkeit durch Druckbeanspr

10、uchung von gekerbten Proben This European Standard was approved by CEN on 15 March 2005. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lis

11、ts and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the respo

12、nsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Irela

13、nd, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-105

14、0 Brussels 2005 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1894:2005: EEN 1894:2005 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Definitions and symbols .4 4 Principle4 5 Apparatus .5 6 Test specimens6 7

15、Test specimen preparation.7 8 Test procedures.8 9 Calculation of results 9 10 Test report 10 Annex A (informative) Examples of types of rupture.11 EN 1894:2005 (E) 3 Foreword This document (EN 1894:2005) has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics”, the secretari

16、at 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 October 2005, and conflicting national standards shall be withdrawn at the latest by October 2005. This document superse

17、des ENV 1894:1996. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland

18、, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 1894:2005 (E) 4 1 Scope This document specifies the conditions for determination of the inter-laminar shear strength of ceramic matrix composite

19、 materials with continuous fibre reinforcement for temperatures up to 2 000 C under a vacuum, or a gas atmosphere, which is inert to the material under test, by loading of notched specimens in compression. NOTE 1 The use of a vacuum or a gas atmosphere is aimed at avoiding changes of the material to

20、 be tested due to chemical reaction with its environment during the test. This document applies to all ceramic matrix composites with continuous fibre reinforcement, unidirectional (1D), bidirectional (2D), and tridirectional (xD, with 2 x 3), loaded along one principal axis of reinforcement. NOTE 2

21、 Care should be exercised in interpreting the results of the test method to obtain absolute values of the inter- laminar shear strength of ceramic matrix composites for design purposes. 2 Normative references The following referenced documents are indispensable for the application of this document.

22、For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 60584-1, Thermocouples; Part 1: Reference tables (IEC 60584-1:1995) EN 60584-2, Thermocouples; Part 2: Tolerances (IEC 60584-2:1982 + A1:

23、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) ISO 3611, Micrometer callipers for external measurement 3 Definitions and symbols For t

24、he purposes of this document, the following definitions and symbols apply. 3.1 test temperature, T temperature at the centre of the test piece 3.2 shear failure force, F maximum force required during a test carried out up to failure 3.3 interlaminar shear strength, ILSS ratio calculated on the basis

25、 of the shear failure force and the shear loaded area 4 Principle The test consists of measuring the force required to fracture a transversely notched test specimen of defined shape and dimensions, heated to the test temperature and subjected to compressive loading in direction 1 or 2, such that fai

26、lure occurs in the form of inter-laminar shear in plane 12. The test is performed at constant crosshead displacement rate. NOTE The test duration is limited to reduce creep effects. EN 1894:2005 (E) 5 5 Apparatus 5.1 Test machine The test machine shall be equipped with a system for measuring the for

27、ce applied to the test specimen conforming to grade 1 or better according to EN ISO 7500-1. NOTE This prevails during actual test conditions, e.g. gas pressure, temperature. 5.2 Load train The load train configuration shall allow alignment of the test specimen axis with the direction of the load. Ca

28、re should be taken to maintain proper alignment of the specimen during loading and to avoid buckling of the specimen. The load train performance including the alignment system and the force transmitting system, shall not change because of heating. Two techniques are possible: compression between pla

29、tens without guide; compression between platens with a guiding tool. The material of the tool shall be compatible with the test specimen material. NOTE When specimens to be tested have a thickness less than 3 mm, the use of a guiding tool is recommended, to avoid buckling. This guide should not caus

30、e any parasitic effect during the test. 5.3 Test chamber The test chamber shall be gas tight and shall allow proper control of the test specimen environment in the vicinity of the test specimen during the test. The installation shall be such that a constant pressure can be maintained during the test

31、. Where a gas atmosphere is used, the gas atmosphere shall be chosen depending on the material to be tested and on test temperature. The level of pressure shall be chosen depending: on the material to be tested, on temperature and on the type of gas. Where a vacuum chamber is used, the level of vacu

32、um shall not induce chemical and/or physical instabilities of the test specimen material. 5.4 Set-up for heating The set-up for heating shall be constructed in such a way that the variation of temperature within the shear- loaded area is less than 20 C at test temperature. 5.5 Temperature measuremen

33、t devices For temperature measurement, either thermocouples conforming to EN 60584-1 and EN 60584-2 shall be used or, where thermocouples not conforming to EN 60584-1 and EN 60584-2 or pyrometers are used, calibration data shall be annexed to the test report. 5.6 Data recording system A calibrated r

34、ecorder may be used to record force-time curve. The use of a digital data recording system combined with an analogue recorder is recommended. EN 1894:2005 (E) 6 5.7 Micrometers Micrometers used for the measurement of the dimensions of the test specimen shall conform to ISO 3611. 6 Test specimens The

35、 test specimens are shown in Figures 1 and 2. A notch is machined on both sides. The recommended specimen dimensions are given in Tables 1 and 2. The notch spacing measured between the inner flanks of the notches (see Figure 1) shall be chosen, taking into account the requirements to obtain shear fa

36、ilure. Figure 1 Test specimen geometry - I Table 1 Test specimen dimensions - I Dimensions in millimetres 1D, 2D, and xD Tolerance L(T), total length 20 to 60 + 1 h, thickness 2 + 0; -0,1 b, width 10 + 0,1 L, distance between notches 8 to 13 + 0,1 Notch depth h/2 + 0,1 + 0,05 d, notch width 0,5 to 2

37、 + 0,1 Parallelism of machined parts 0,05 EN 1894:2005 (E) 7 Figure 2 Test specimen geometry - II Table 2 Test specimen dimensions - II Dimensions in millimetres 1D, 2D and xD Tolerance h, thickness 2 0,2 b, width 8 to 20 0,2 Parallelism of machined parts 0,05 NOTE (Applies to Figures 1 and 2) If th

38、e proposed notch depth (h/2 + 0,1) does not lead to a rupture in a shear plane, then the depth of the notch can be increased to: () 2 1 n n + h where h is the thickness, in millimetres (mm); n is the number of plies. If the specimen is coated, the thickness of coating shall be added to the thickness

39、. 7 Test specimen preparation 7.1 Machining and preparation During cutting out, care shall be taken to align the test specimen axis with the desired fibre related loading axis. Machining parameters that avoid damage to the material shall be established and documented. These parameters shall be adher

40、ed to during test specimen preparation. 7.2 Number of test specimens At least five valid test results, as specified in 8.4, are required for any condition. EN 1894:2005 (E) 8 8 Test procedures 8.1 Test set-up: Temperature considerations The following determinations shall be carried out under conditi

41、ons representative of the tests, and shall be repeated every time there is a change, e.g. in material, in specimen geometry, in gripping configuration. In establishing them, time shall be allowed for temperature stabilization. Prior to testing, the temperature gradient within the shear zone shall be

42、 established over the temperature range of interest. This shall be done by measuring the specimen temperature at a minimum of three locations, which shall be over the notches and midway between the two. The temperature variation in the shear-loaded area shall meet the requirements of 5.4. Temperatur

43、es shall be measured in accordance with 5.5. If thermocouples are used to measure the temperature at different locations of the specimen, they shall be embedded (and sealed if necessary) into a dummy specimen to a depth approximately equal to half the specimen dimension in the direction of insertion

44、. During a series of tests, the test temperature may be determined either directly by measurement on the specimen itself, or indirectly from the temperature indicated by the temperature control device. In the latter case, calibration will be necessary. The relationship between the control temperatur

45、e and test specimen temperature at the centre of the gauge length shall be established beforehand on a dummy test specimen over the range of temperature of interest. NOTE The relationship between the temperature indicated by the temperature control system and the test temperature is usually establis

46、hed simultaneously with the temperature gradient. 8.2 Test set-up: Other considerations 8.2.1 Displacement rate A constant cross head speed that allows completion of the test within 1 min shall be used and the speed used shall be recorded. If material to be tested is sensitive to creep at the temper

47、ature of test, the speed shall be significantly increased but impact loading shall be avoided. 8.2.2 Measurement of test specimen dimensions The width shall be measured to the nearest 0,01 mm in the centre and at each end of the shear loaded area, and the distance between the notches shall be measur

48、ed to an accuracy of + 0,1 mm. NOTE Dimensions vary with temperature and variations are difficult to measure, therefore dimensions are measured at room temperature. The arithmetic means of the measurements shall be used for calculations. If thermal expansion between room temperature and the temperat

49、ure of test is less than the tolerance on the measurements, then the measurements can be made at room temperature. If this is not the case, the measurements shall be corrected to take the thermal expansion into account, or shall be measured at temperature. 8.3 Testing technique 8.3.1 Specimen mounting Install the test specimen in the loading system with its longitudinal axis coinciding with that of the test machine. EN 1894:2005 (E) 9 8.3.2 Setting of inert atmosphere When t