BS EN 15365-2010 Advanced technical ceramics Mechanical properties of ceramic fibres at high temperature in a non-reactive environment Determination of creep behaviour by the cold .pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 15365:2010Advanced technical ceramics Mechanical propertiesof ceramic fibres at hightemperature in a non-reactiveenvironment Determinationof creep behaviour by the coldend

2、methodBS EN 15365:2010 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 15365:2010.The UK participation in its preparation was entrusted to TechnicalCommittee RPI/13, Advanced technical ceramics.A list of organizations represented on this committee can beobtained

3、 on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 69296 3ICS 81.060.30Compliance with a British Standard cannot confer immunity fromlegal obligations.This Briti

4、sh Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2010Amendments issued since publicationDate Text affectedBS EN 15365:2010EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15365 July 2010 ICS 81.060.30 Supersedes CEN/TS 15365:2006English Ver

5、sion Advanced technical ceramics - Mechanical properties of ceramic fibres at high temperature in a non-reactive environment - Determination of creep behaviour by the cold end method Cramiques techniques avances - Proprits mcaniques des fibres cramiques haute temprature sous environnement non-ractif

6、 - Dtermination du comportement au fluage par la mthode des mors froids Hochleistungskeramik - Mechanische Eigenschaften von Keramikfasern bei hohen Temperaturen in einer reaktionsfreien Umgebung - Bestimmung des Kriechverhaltens im Kaltverbindungsverfahren This European Standard was approved by CEN

7、 on 25 June 2010. 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 lists and bibliographical references concerning such national standards ma

8、y 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 translation under the responsibility of a CEN member into its own language and notified to the C

9、EN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,

10、 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 2010 CEN All rights of exploit

11、ation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15365:2010: EBS EN 15365:2010EN 15365:2010 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Principle 75 Significance and use .86 Apparatus .86.1 Test installations86

12、.2 Load train 86.3 Test chamber 96.4 Set-up for heating 96.5 Temperature measurement .96.6 Control of deformation 96.7 Data recording system 96.8 Determination of fibre cross sectional area 97 Test specimens 97.1 Test specimen preparation .97.2 Number of test specimens . 118 Test procedures 118.1 De

13、termination of the temperature profile in the furnace 118.2 Test set-up: Determination of the temperature profile and of the different lengths of each temperature zone in the furnace . 118.3 Test set-up: Loading considerations 128.4 Test technique . 128.5 Test validity . 149 Calculation of results .

14、 149.1 Creep stress 149.2 Creep strain at time t 1410 Test report . 15Bibliography . 17BS EN 15365:2010EN 15365:2010 (E) 3 Foreword This document (EN 15365:2010) has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics”, the secretariat of which is held by BSI. This European

15、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 2011, and conflicting national standards shall be withdrawn at the latest by January 2011. Attention is drawn to the possibility that some of the elements

16、 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. This document supersedes CEN/TS 15365:2006. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following

17、countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,

18、Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 15365:2010EN 15365:2010 (E) 4 1 Scope This European Standard specifies the conditions for the determination of the tensile creep deformation and failure behaviour of single filaments of ceramic fibres at high temperature and under te

19、st conditions that prevent changes to the material as a result of chemical reaction with the test environment. This European Standard applies to continuous ceramic filaments taken from tows, yarns, braids and knittings, which have strains to fracture less than or equal to 5 %. 2 Normative references

20、 The following 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 60584 (all parts), Thermocouples CEN/TR 13233

21、:2007, Advanced technical ceramics Notations and symbols 3 Terms and definitions For the purposes of this document, the terms and definitions given in CEN/TR 13233:2007 and the following apply. 3.1 creep time-dependent increase of gauge length starting from the time when the constant specified level

22、 of force is reached 3.2 creep threshold temperature Ttminimum temperature at which creep is detected 3.3 specimen temperature T temperature which varies along the fibre length in the cold grips case NOTE See 8.2. 3.4 specimen temperature in the zone Ti temperature defined as: Tt Ti Tt+ i T 3.5 tota

23、l length L total length of the ceramic filament between the grips 3.6 length Lilength of the ceramic filament at temperature TiBS EN 15365:2010EN 15365:2010 (E) 5 3.7 initial effective cross sectional area A0initial cross sectional area of the ceramic filament within the gauge length 3.8 applied ten

24、sile force F constant force applied to the ceramic filament during the test 3.9 applied tensile stress applied tensile force divided by the initial cross sectional area 3.10 longitudinal deformation L change in the total length of the ceramic filament caused by creep 3.11 longitudinal deformation Li

25、change of the filament caused by creep at temperature Ti3.12 tensile creep strain cr(T)relative change in length in the controlled zone at time t, caused by creep at the temperature T NOTE The value corresponding to rupture is denoted cr,m. 3.13 creep rupture time tcr,mtime elapsed from the moment w

26、hen loading is completed until the moment of rupture 3.14 creep strain rate LTis the furnace length where the temperature T is in the range Tt T Tt+ T. Figure 2 Temperature profile in furnace If Ttis considered to be the lowest temperature at which creep is observed, the temperature profile can be d

27、ivided in several intervals as a function of Ttand T, where T is the difference in temperature between the different zones, fixed by the operator. If we consider i, the entire number of zones, and L, the total fibre length, then we can define the following lengths: L20is the furnace length where the

28、 temperature T is in the range 20 C T Tt; BS EN 15365:2010EN 15365:2010 (E) 8 LTis the furnace length where the temperature T is in the range Tt T Tt+ T; L2Tis the furnace length where the temperature T is in the range Tt+ T T Tt+ 2 T; LiTis the furnace length where the temperature T is in the range

29、 Tt+ (i 1) T T Tt+ i T. Then L can be written: L = L20+ LT+ L2T+ L3T+ + LiT (1) Thus it is possible to determine the deformation in all of these different temperature zones. The inconvenience of this method is that determining the true deformation in the L2Tzone requires the determination of the def

30、ormation in the lower temperature zones. Below the temperature Ttand for a constant load applied to the fibre, the deformation is constant so that the strain rate is equal to zero. 5 Significance and use Creep tests allow the comparison and the determination of parameters or behaviour laws and their

31、 extrapolation to long-term behaviour for different materials under constant load at high temperatures. These allow the conception and design of industrial parts with close control of tolerances for high temperature applications. 6 Apparatus 6.1 Test installations NOTE Two different types of install

32、ation can be used, as specified in 6.1.1 and 6.1.2. 6.1.1 Test machine The machine shall be equipped with a system for measuring the force applied to the test specimen. The machine shall have a load cell with a resolution of 10-3N for the applied force. The displacement transducer shall have a resol

33、ution of at least 2 . This shall prevail during actual test conditions (pressure, temperature). 6.1.2 Creep testing rig When a creep testing rig is used, the force application system shall be calibrated. The testing rig shall be equipped with a system to allow smooth loading of the ceramic filament(

34、s). When this system is used, care shall be taken to ensure that the force applied to the ceramic filament remains constant to within 10-3N, even when the material properties change and the environmental conditions (temperature, pressure) fluctuate. 6.2 Load train The gripping system shall align the

35、 test specimen axis with that of the applied force. The load train configuration shall ensure that the load indicated by the load cell and the load experienced by the test specimen are the same. The load train performance including the alignment and the force transmission shall not change because of

36、 heating. BS EN 15365:2010EN 15365:2010 (E) 9 6.3 Test chamber 6.3.1 General The chamber shall allow proper control of the test specimen environment during the test and ensure that any variation of load during the test is less than 1 % of the scale of the load cell being used. 6.3.2 Gaseous environm

37、ent The gaseous environment shall be chosen depending on the material to be tested and on the test temperature. If the test is conducted in flowing gas, the rate of flow should be sufficiently high to exclude oxygen, but not so as to induce turbulence in the furnace. If a closed system is used the l

38、evel of pressure shall be chosen depending on the material to be tested, on temperature, on the type of gas and on the type of extensometry. 6.3.3 Vacuum chamber The level of vacuum shall not induce chemical and/or physical instabilities of the filament. 6.4 Set-up for heating The set-up for heating

39、 shall be constructed in such a way that the variation of temperature within the gauge length is known to within 20 K. NOTE Horizontal furnaces give a more symmetrical temperature profile than vertical devices. 6.5 Temperature measurement For temperature measurement, either thermocouples conforming

40、to EN 60584 (all parts) shall be used, or, where thermocouples not conforming to EN 60584 (all parts) or pyrometers are used, they shall be appropriately calibrated and the calibration data added to the test report. 6.6 Control of deformation The deformation of the filament can be measured by the mo

41、vement of the cross-head, with compensation being made for the compliance of the machine according to EN 1007-4. A direct technique for measuring the deformation of the filament is by speckle interferometry. 6.7 Data recording system Calibrated recorders may be used to record force, longitudinal def

42、ormation and temperature versus time. 6.8 Determination of fibre cross sectional area The fibre cross sectional area can be determined from a measurement of the fibre diameter, if the fibre is circular in section, or an average diameter can be determined if it is not. Measurements should conform to

43、EN 1007-3. 7 Test specimens 7.1 Test specimen preparation Extreme care shall be taken during test specimen preparation to ensure that the procedure is repeatable from test specimen to test specimen and to avoid handling damage. BS EN 15365:2010EN 15365:2010 (E) 10 NOTE 1 The introduction of damage d

44、uring test specimen preparation may result in a truncation of the strength distribution and is more critical the longer the length of the filament. NOTE 2 During test specimen preparation and in particular when extracting a filament from the tow, the ratio of damaged filaments to the total number of

45、 extracted filaments should be minimised. NOTE 3 To prevent damage during test specimen manipulation and mounting, an example of the assembly of a test specimen is shown in Figure 3. This test specimen preparation uses a mounting tab of thin paper, metal or plastic cut as shown in Figure 3, with a w

46、indow. The length of the window is equal to the gauge length of the filament test specimen. An adhesive, suitable for affixing the filament to the ends of mounting tab, such as an epoxy resin, a cement or sealing wax, is used for this purpose. NOTE 4 Another example of assembly, shown in Figure 4, c

47、an be used to prevent damage during test specimen manipulation and mounting. Dimensions in millimetres Key a Filament b Glue L1See Table 1 for dimensions L2See Table 1 for dimensions Figure 3 Assembly of test specimen BS EN 15365:2010EN 15365:2010 (E) 11 Table 1 Dimensions of L1and L2L1mm L2mm 10 0,

48、5 30 1 25 0,5 45 1 50 0,5 70 1 Key 1 Alumina tubes 2 Temporary screw attachment 3 Test specimen 4 Ceramic cement 5 Alumina rod Figure 4 Alternative test specimen assembly 7.2 Number of test specimens At least three valid test results by temperature and by load are required. 8 Test procedures 8.1 Det

49、ermination of the temperature profile in the furnace The following procedures shall be carried out under conditions representative of the tests and shall be repeated every time there is a change in gripping configuration, etc. 8.2 Test set-up: Determination of the temperature profile and of the different lengths of each temperature zone in the furnace Prior to testing, the tem