1、November 2010 Translation by DIN-Sprachendienst.English price group 9No part of this translation 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).IC
2、S 81.060.30!$l1i“1731470www.din.deDDIN EN 843-7Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature Part 7: C-ring testsEnglish translation of DIN EN 843-7:2010-11Hochleistungskeramik Mechanische Eigenschaften monolithischer Keramik bei Raumtemperatur Teil 7:
3、C-Ring-PrfungenEnglische bersetzung von DIN EN 843-7:2010-11Cramiques techniques avances Proprits mcaniques des cramiques monolithiques temprature ambiante Partie 7: Essais dchantillons en forme danneau en CTraduction anglaise de DIN EN 843-7:2010-11www.beuth.deDocument comprises pagesIn case of dou
4、bt, the German-language original shall be considered authoritative.141 .10 0DIN EN 843-7:2010-11 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics” (Secretariat: BSI, United Kingdom). The responsibl
5、e German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Working Committee NA 062-02-91 AA Prfung von Hochleistungs-keramik Monolithische Werkstoffe. The DIN Standards corresponding to the International Standards referred to in this do
6、cument are as follows: ISO 3611 DIN 863-1 ISO 6906 DIN 862 National Annex NA (informative) Bibliography DIN 862, Vernier callipers Requirements and testing DIN 863-1, Verification of geometrical parameters Micrometers Part 1: Standard design micrometer callipers for external measurement oncepts, req
7、uirements, testing C2 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 843-7 June 2010 ICS 81.060.30 English Version Advanced technical ceramics - Mechanical properties of monolithic ceramics at room temperature - Part 7: C-ring tests Cramiques techniques avances - Proprits mcaniques des cramiqu
8、es monolithiques temprature ambiante - Partie 7: Essais dchantillons en forme danneau en C Hochleistungskeramik - Mechanische Eigenschaften monolithischer Keramik bei Raumtemperatur - Teil 7: C-Ring-Prfungen This European Standard was approved by CEN on 13 May 2010. CEN members are bound to comply w
9、ith 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 may be obtained on application to the CEN Management
10、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 CEN Management Centre has the same status as the off
11、icial 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, Netherlands, Norway, Poland, Portugal, Romania, Sl
12、ovakia, 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 exploitation in any form and by any means reserved worldwi
13、de for CEN national Members. Ref. No. EN 843-7:2010: EEN 843-7:2010 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Definitions 44 Significance and use .45 Principle 55.1 Method A: C-ring compression 55.2 Method B: C-ring tension 56 Apparatus .66.1 Cutting machine .66.2 Vernier call
14、ipers .66.3 Micrometer callipers 66.4 Mechanical testing machine .76.5 Interface material .77 Test pieces .78 Test procedure .88.1 Test-piece dimensions 88.2 Mechanical testing .89 Calculation 89.1 Method A: C-ring compression 89.2 Method B: C-ring tension test 99.3 Mean and standard deviation .99.4
15、 Fractures away from the centre-line 910 Interferences 911 Report 10Annex A (informative) C-ring compliance 11Bibliography . 12DIN EN 843-7:2010-11 EN 843-7:2010 (E) 3 Foreword This document (EN 843-7:2010) has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics”, the secret
16、ariat 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 December 2010, and conflicting national standards shall be withdrawn at the latest by December 2010. Attention is dra
17、wn 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. EN 843, Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature,
18、consists of the following nine parts: 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 Rock
19、well superficial hardness tests Part 5: Statistical analysis Part 6: Guidance for fractographic investigation Part 7: C-ring tests Part 8: Guidelines for conducting proof tests FprCEN/TS 843-9, Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature Part 9: Metho
20、d of test for edge-chip resistance According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany
21、, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 843-7:2010-11 EN 843-7:2010 (E) 4 1 Scope This European Standard describes a method for unde
22、rtaking ultimate strength tests on slotted rings (C-rings) in order to determine the strength of ring or tube-shaped components in the manufactured geometry. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only t
23、he edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 843-5:2006, Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature Part 5: Statistical analysis EN 1006, Advanced technical cer
24、amics Monolithic ceramics Guidance on the selection of test pieces for the evaluation of properties EN ISO 7500-1:2004, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system (ISO 750
25、0-1:2004) EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC 17025:2005) ISO 3611:1978, Micrometer callipers for external measurement ISO 6906:1984, Vernier callipers reading to 0,02 mm 3 Definitions For the purposes of this document, the follo
26、wing terms and definitions apply. 3.1 C-ring test piece ring-shaped test piece in which a radial slot has been cut to convert it into an incomplete ring 3.2 C-ring compression test test in which a C-ring test piece is compressed across a diameter away from the slot, and which imposes the maximum ten
27、sile stress on the outside surface of the ring remote from the points of compression load application 3.3 C-ring tension test test in which a C-ring test piece is pulled across a diameter away from the slot, and which imposes the maximum tensile stress on the inside surface of the ring remote from t
28、he point of tensile load application 4 Significance and use This method of test permits the strength of circular symmetry test pieces such as thin-walled rings or tubes to be determined. The diametral loading of a short length of slotted tube or a slotted ring produces a tensile stress in the mid-se
29、ction of the tube wall, either in the outside region of the wall thickness if the ring is compressed, or in the inside region if the ring is pulled in tension. In both cases the maximum stresses are in DIN EN 843-7:2010-11 EN 843-7:2010 (E) 5 the tube surface, and are remote from the points of load
30、application, and thus only weakly influenced by the precise geometry of load application. In contrast, diametral compression of a ring without a slot leads to high tensile stresses immediately opposite the points of load application, with much poorer calibration and greater sensitivity to the precis
31、e geometry of loading. The result of a C-ring test is sensitive to the surface finish applied to the cylindrical surfaces of the ring, for example by the method of shaping the article, and additionally to the planar ring faces. Thus if a ring is cut from a tube, the cutting shall be done in such a m
32、anner as not to influence the result of the test if the purpose of the test is to determine the as manufactured tube strength. The results obtained from this test are representative of the strength of pressurized tubes and other cylindrical shapes. 5 Principle 5.1 Method A: C-ring compression A slot
33、ted ring test-piece is placed on its cylindrical surface on a flat anvil of a mechanical testing machine with the slot remote from anvil (Figure 1a). The second anvil of the test machine is brought into contact with the top surface of the ring, and the load is increased until failure occurs by closi
34、ng the C-ring. The strength is computed from the ring geometry and the maximum force applied. 5.2 Method B: C-ring tension Two opposed horizontal pull bars connected to a mechanical testing machine are used to contact the slotted ring at diametrally opposed positions remote from the slot (Figure 1b)
35、. The force is increased until failure by opening the ring. The strength is computed from the ring geometry and the maximum force applied. DIN EN 843-7:2010-11 EN 843-7:2010 (E) 6 rirorcPPrirortPPa) C-ring test in compression b) C-ring test in tension Key angle between the mid-plane and the location
36、 of the crack developed during the test rcC-ring strength determined in compression mode rtC-ring strength determined in ring tension mode r0outside wall tube radius riinside wall tube radius P applied load Figure 1 C-ring test in compression and in tension 6 Apparatus 6.1 Cutting machine A cutting
37、machine equipped with a diamond saw blade suitable for preparing parallel faced slices from tube material. The saw blade may be selected to be appropriate for the material being cut, but the grit size should be minimised, and the cutting process adjusted to minimise edge chipping and other damage. I
38、f the available machine does not cut adequately dimensioned test-pieces (see Clause 7), test-pieces may be subsequently ground or lapped flat and parallel faced using other appropriate machines. 6.2 Vernier callipers Vernier callipers reading to 0,02 mm in accordance with ISO 6906:1984, but addition
39、ally equipped with the ability to measure internal diameters of test pieces, or other suitable measurement device of equivalent accuracy. 6.3 Micrometer callipers Micrometer callipers reading to 0,01 mm or better in accordance with ISO 3611:1978, or other suitable measurement device of equivalent ac
40、curacy. DIN EN 843-7:2010-11 EN 843-7:2010 (E) 7 NOTE Micrometer callipers with flat anvils are normally recommended for making measurements on ceramic materials to avoid risks of indentation associated with rounded anvils. However, rounded anvils will be required for measuring wall thickness, and s
41、hould be used with considerable caution. 6.4 Mechanical testing machine A mechanical testing machine capable of applying a force to the test jig at a constant displacement rate or at constant loading rate. The testing machine shall be equipped for recording the load applied to the test jig at any po
42、int in time. The accuracy and calibration of the testing machine shall be in accordance with EN ISO 7500-1:2004, Grade 1 (1 % of indicated load). For Method A, the testing machine shall be equipped with hard flat anvils with faces either fixed parallel to within 0,05 mm over the area to be used for
43、testing, or self-aligning during testing. For Method B, the testing machine shall be equipped with a device for permitting two hard steel rollers to be inserted through the ring and supported at each end by yokes connected to the testing machine which permit a tensile force to be applied. Universal
44、joints shall be incorporated into the load train to permit alignment and to minimise stress concentrations towards one face or other of the ring. NOTE Any suitable alternative arrangement may be used in which the load can be applied in compression mode using a lever system containing the loading rol
45、lers. Precautions shall be taken to avoid flying fragments from the test-piece during fracture. 6.5 Interface material Thin, compliant materials such as cardboard, metal foil or rubber sheet, to be placed between the test piece and the compression anvils (Method A) or steel rollers (Method B). 7 Tes
46、t pieces Test pieces or test material shall be selected in accordance with the guidelines in EN 1006. If the test rings are to be cut from tube stock, select stock which is acceptably round and straight. This standard does not prescribe any particular dimensions for test pieces, but the following si
47、ze ratios are recommended to avoid problems with alignment or validity of the calculation equations: a) 0,05 (wall thickness/outer ring radius) 0,5; b) 0,2 (axial length/outer ring radius) 1,0; c) 1,0 (axial length/wall thickness) 4,0. Cut or otherwise machine the side faces of the test pieces to a
48、parallelism of better than 0,015 mm using a diamond saw with or without additional machining by lapping or surface grinding. This process shall introduce a minimum of damage such that failure does not occur from the cut face. NOTE 1 Guidance on machining processes may be found in EN 843-1 6 and ASTM
49、 C1495 1. Make an axial cut through the wall of the ring using a diamond saw. For Method A the slot width shall be sufficiently large that the sides of the slot do not close during the test before failure of the test-piece. For thick-walled test-pieces, a slot of 1 mm to 2 mm is adequate, but for thinner walled test-pieces, the slot shall be rather wider. All edges shall be chamfered at 45 to a distance of at least (0,15
