1、BS EN1071-9:2009ICS 81.060.30NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDAdvanced technicalceramics Methodsof test for ceramiccoatingsPart 9: Determination of fracturestrainCopyright European Committee for Standardization Provided by IHS under license with C
2、ENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-This British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 August2009 BSI 2009ISBN 978 0 580 63848 0Amendments/corrigenda issued since publicationDate CommentsBS EN 1071
3、-9:2009National forewordThis British Standard is the UK implementation of EN 1071-9:2009.The UK participation in its preparation was entrusted to TechnicalCommittee RPI/13, Advanced technical ceramics.A list of organizations represented on this committee can be obtained onrequest to its secretary.Th
4、is publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.Copyright European Committee for Standardization Provided by IHS under license with
5、CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 1071-9:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 1071-9July 2009ICS 81.060.30 Supersedes CEN/TS 1071-9:2004 English VersionAdvanced technical ceramics - Methods of test for ceramiccoatings - Part
6、9: Determination of fracture strainCramiques techniques avances - Mthodes dessai pourrevtements cramiques - Partie 9 : Dtermination de ladformation la ruptureHochleistungskeramik - Verfahren zur Prfung keramischerSchichten - Teil 9: Bestimmung der BruchdehnungThis European Standard was approved by C
7、EN on 19 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 concerning such nationalstandards may
8、 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 own language and notified to the CEN
9、Management Centre has the same status as theofficial 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, Lithuania, Luxembourg, Malta, Netherlands, N
10、orway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form an
11、d by any means reservedworldwide for CEN national Members.Ref. No. EN 1071-9:2009: ECopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 1071-9:2009EN 1071-9:2009 (E) 2 Contents
12、 Page Foreword . 3 Introduction 5 1 Scope 6 2 Normative references . 6 3 Terms and definitions . 6 4 Significance and use 8 5 Principle . 8 6 Apparatus and materials 8 6.1 Instrumentation . 8 6.2 Specimen preparation 9 7 Test procedure 11 7.1 Calibration . 11 7.2 Sample loading 11 7.3 Strain determi
13、nation . 11 7.4 Crack detection . 11 7.5 Test parameters 12 8 Report . 12 Bibliography . 15 Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 1071-9:2009EN 1071-9:2009 (E) 3
14、Foreword This document (EN 1071-9:2009) 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, a
15、t the latest by January 2010, and 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 an
16、y or all such patent rights. This document supersedes CEN/TS 1071-9:2004. EN 1071 Advanced technical ceramics Methods of test for ceramic coatings consists of the following parts: Part 1: Determination of coating thickness by contact probe profilometer Part 2: Determination of coating thickness by t
17、he crater grinding method Part 3: Determination of adhesion and other mechanical failure modes by a scratch test Part 4: Determination of chemical composition by electron probe microanalysis (EPMA) Part 5: Determination of porosity withdrawn Part 6: Determination of the abrasion resistance of coatin
18、gs by a micro-abrasion wear test Part 7: Determination of hardness and Youngs modulus by instrumented indentation testing withdrawn Part 8: Rockwell indentation test for evaluation of adhesion Part 9: Determination of fracture strain Part 10: Determination of coating thickness by cross sectioning Pa
19、rt 11: Determination of internal stress by the Stoney formula Part 12: Reciprocating wear test 1) Part 13: Determination of wear rate by the pin-on-disk method 1)Parts 7, 8 and 11 are Technical Specifications. Part 7 was withdrawn shortly after publication of EN ISO 14577-4:2007. 1)In preparation at
20、 the time of publication of this European Standard. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 1071-9:2009EN 1071-9:2009 (E) 4 According to the CEN/CENELEC Internal Re
21、gulations, the national standards 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, Ne
22、therlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 1071-9:
23、2009EN 1071-9:2009 (E) 5 Introduction The fracture strain of a coating is a critical factor often determining the performance of a coated product. Clearly if stressed either directly or due to thermal effects (thermal expansion coefficient mismatch between the coating and substrate) coating cracking
24、 can occur if the critical fracture stress/strain is exceeded, and in many cases the effectiveness of the coating will be reduced. For example, corrosion resistant coatings lose their protective character if cracking occurs, and optical coatings become ineffective when cracked. In many cases crackin
25、g is the first stage of a much more serious form of failure in which large areas of the coating can spall. The extent to which coated components can withstand external applied loads is an important property in the application of any coated system, and usually it is necessary to know the failure stre
26、ss. For calculation of the stress both the fracture strain and Youngs modulus of the coating should be known. EN ISO 14577-4 1, which replaced Technical Specification CEN/TS 1071-7, can be used to measure the Youngs modulus by depth sensing indentation, but there are other methods involving flexure
27、and impact excitation that may also be applied 2, 3. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 1071-9:2009EN 1071-9:2009 (E) 6 1 Scope This part of EN 1071 describes
28、a method of measuring the fracture strain of ceramic coatings by means of uniaxial tension or compression tests coupled with acoustic emission to monitor the onset of cracking of the coating. Tensile or compressive strains can also be applied by flexure using four-point bending. Measurements can be
29、made in favourable cases at elevated temperatures as well as at room temperature. 2 Normative references 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
30、referenced document (including any amendments) applies. EN 10002-1, Metallic materials Tensile testing Part 1: Method of test at ambient temperature EN 10002-5, Metallic materials Tensile testing Part 5: Method of testing at elevated temperature EN ISO/IEC 17025, General requirements for the compete
31、nce of testing and calibration laboratories (ISO/IEC 17025:2005) ISO 12106, Metallic materials Fatigue testing Axial-strain-controlled method 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 fracture strain strain required to create a detectab
32、le crack in the coating NOTE The presence of the crack can be detected using optical or scanning electron microscopy, or indirectly using acoustic emission signals. 3.2 acoustic emission AE generation of acoustic signals that are recorded as hits, counts, energy or amplitude NOTE See Figure 1 for de
33、finition of AE signals. 3.3 AE hit single acoustic event above a set threshold 3.4 AE energy area of the waveform of an AE hit 3.5 AE amplitude peak of the waveform of an AE hit Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or ne
34、tworking permitted without license from IHS-,-,-BS EN 1071-9:2009EN 1071-9:2009 (E) 7 3.6 AE counts number of times the AE waveform passes a set threshold within a single hit 3.7 AE threshold arbitrary AE amplitude at which AE hits are deemed to be significant and above the AE signals generated by t
35、he test equipment 3.8 waveguide metallic wire connecting (usually by spot welding) the sample to the AE transducer 12478910563Key 1 Volts 6 Time 2 Rise time 7 Threshold crossing 3 Amplitude 8 Counts 4 Energy 9 Time 5 Threshold 10 Duration Figure 1 - Schematic representation of AE signals Copyright E
36、uropean Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 1071-9:2009EN 1071-9:2009 (E) 8 4 Significance and use This test procedure covers the measurement of fracture strain in tension or comp
37、ression in coatings subject to mechanical stress at ambient or elevated temperature. The method is applicable to cases where the substrate is sufficiently ductile such that fracture of the coating occurs before the substrate. In addition, if during plastic deformation of the substrate acoustic signa
38、ls are generated, this may interfere with those caused by coating fracture. Where possible it is recommended that a test be carried out with the uncoated substrate to determine whether such extraneous AE signals occur. 5 Principle Specimens of appropriate geometry are submitted to a mechanical stres
39、s; the subsequent strain is measured and the onset of coating failure is detected. The test draws upon the expertise of standard tensile and compressive tests but requires additional care due to the precision required of the measurements. The applied stress may be tensile or compressive and may be a
40、pplied directly or in flexure. The test shall be carried out to satisfy the requirements of accepted standards for mechanical testing of materials under the selected method of loading. NOTE 1 Detection of the fracture of coatings can be carried in a number of ways. The most convenient is to use acou
41、stic emission (AE), which allows continuous monitoring of the specimen. Acoustic signals are produced when a crack forms. These signals are captured using suitable detectors and the signals generated are then analysed. In many cases a waveguide is used to carry the signal from the specimen to the de
42、tector; this waveguide is normally a metallic material. Use of two AE detectors can help to eliminate extraneous signals coming from the loading mechanism. Commercially available AE systems can be used for this work. NOTE 2 Where AE cannot be used, crack detection is possible by high resolution vide
43、o systems, which may allow continuous monitoring. Alternatively, optical or scanning electron microscopy can be used to examine the samples. Normally this is done post-test, but in situ examination is also possible. 6 Apparatus and materials 6.1 Instrumentation 6.1.1 In simplest terms the equipment
44、required is a mechanism to apply load to the specimen; extensometry to measure the strain; and apparatus to detect/monitor fracture of the surface layer. Load is normally applied continuously through servo-electric testing machines; the load capacity of the frame should be sufficient to allow strain
45、ing of the specimen to beyond the yield point of the substrate material. Continuation of the test to complete separation of the specimen is not normally required. 6.1.2 For flexural testing a suitable test jig is required four-point bending is recommended as this applies more uniform bending moment
46、over the gauge length. A suitable jig is shown in Figure 2. 6.1.3 Extensometry should be sufficiently precise to measure strain at a resolution of 0,01%. 6.1.4 For tests at high temperatures using the uniaxial test configuration a furnace is required which allows access for attachment of load frame,
47、 extensometry, thermocouples and waveguides to transmit the AE signals to the AE detector(s). For the four-point bend configuration, an oxidation resistant jig shall be used. NOTE Deformation of oxide layers formed on a metallic jig will probably contribute to AE signals during the test. Copyright E
48、uropean Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN 1071-9:2009EN 1071-9:2009 (E) 9 6.1.5 Crack detection in the coating may be performed visually or by monitoring AE. Visual inspection requires suitable long focal length video facilities with a field of view containing the gauge length. At high temperatures the availability of a cool path to the video camera is also required to avoid shimmer of the image. 13
