BS ISO 13314-2012 Mechanical testing of metals Ductility testing Compression test for porous and cellular metals《金属的机械试验 延展性试验 多孔状和蜂窝状金属的压缩试验》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 13314:2011Mechanical testing ofmetals Ductility testing Compression test for porousand cellular metalsBS ISO 13314:2011 BRITISH STANDARDNational forewordThis British Stand

2、ard is the UK implementation of ISO 13314:2011.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/101/2, Ductility testing.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all th

3、e necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012ISBN 978 0 580 67814 1ICS 77.040.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of t

4、heStandards Policy and Strategy Committee on 31 January 2012.Amendments issued since publicationDate Text affectedBS ISO 13314:2011Reference numberISO 13314:2011(E)ISO 2011INTERNATIONAL STANDARD ISO13314First edition2011-12-15Mechanical testing of metals Ductility testing Compression test for porous

5、 and cellular metals Essais mcaniques des mtaux Essais de ductilit Essai de compression des mtaux poreux et cellulaires BS ISO 13314:2011ISO 13314:2011(E) COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized

6、in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41

7、22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 13314:2011ISO 13314:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introduction . v 1 Scope 1 2 Normative references 1 3 Terms and definitions . 1 4 Principle . 4 5

8、Apparatus . 4 6 Test specimen 4 6.1 Geometry 4 6.2 Number of test specimens . 4 6.3 Sampling of test specimen . 4 7 Test procedure . 5 7.1 Test temperature 5 7.2 Measurement of initial dimensions of test specimen 5 7.3 Test speed 5 7.4 General conduct of test 6 7.5 Preliminary test and unloading tes

9、t 6 7.6 Zero point for the compressive strain . 6 7.7 Energy absorption and energy absorption efficiency . 6 8 Test report 7 8.1 General information 7 8.2 Optional information . 7 BS ISO 13314:2011ISO 13314:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Stand

10、ardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right

11、to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International St

12、andards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an I

13、nternational Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 133

14、14 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee SC 2, Ductility testing. BS ISO 13314:2011ISO 13314:2011(E) ISO 2011 All rights reserved vIntroduction Porous and cellular metals have attractive properties due to their unique cell morphology. When they ar

15、e used as a crush energy absorbing component of automotive machines, compressive properties are necessary for industrial design. However, the deformation behaviour of porous metals and metallic foams is quite different from conventional dense metals. Test methods for conventional metallic materials

16、are not suitable for porous metals and metallic foams. Standardization of a test method for porous metals and metallic foams is required. BS ISO 13314:2011BS ISO 13314:2011INTERNATIONAL STANDARD ISO 13314:2011(E) ISO 2011 All rights reserved 1Mechanical testing of metals Ductility testing Compressio

17、n test for porous and cellular metals 1 Scope This International Standard specifies a test method for compressive properties of porous and cellular metals with a porosity of 50 % or more. Compressive tests can be carried out at ambient temperature under quasi-static strain rate conditions. 2 Normati

18、ve 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 referenced document (including any amendments) applies. ISO 7500-1, Metallic materials Veri

19、fication of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system ISO 9513, Metallic materials Calibration of extensometers used in uniaxial testing 3 Terms and definitions For the purposes of this document, the follo

20、wing terms and definitions apply. 3.1 compressive stress compressive force divided by the initial cross-sectional area perpendicular to the loading direction NOTE Compressive stress is expressed in newtons per square millimetre. 3.2 compressive strain e overall compressive displacement divided by th

21、e initial height (gauge length) of the test specimen NOTE Compressive strain is expressed as a percentage. 3.3 first maximum compressive strength compressive stress corresponding to the first local maximum in the stress-strain curve See Figure 1. NOTE It cannot be determined if no local maximum occu

22、rs. BS ISO 13314:2011ISO 13314:2011(E) 2 ISO 2011 All rights reserved3.4 plateau stress plarithmetical mean of the stresses at 0,1 % or smaller strain intervals between 20 % and 30 % or 20 % and 40 % compressive strain See Figure 1. NOTE The strain range/interval, 20 % and 30 % or 20 % and 40 %, for

23、 arithmetical mean varies depending on the plateau end strain. 3.5 plateau end point in the stress-strain curve at which the stress is 1,3 times the plateau stress See Figure 1. NOTE If this point does not adequately represent the end of the plateau range, another stress can be selected which corres

24、ponds to the curve trace (see 7.4). 3.6 energy absorption W area under the stress-strain curve up to 50 % strain or up to the plateau end strain, epleNOTE The energy absorption up to other strain values can also be determined (see 7.7). 3.7 energy absorption efficiency Weenergy absorption divided by

25、 the product of the maximum compressive stress within the strain range and the magnitude of the strain range 3.8 quasi-elastic gradient gradient of the straight line determined within the linear deformation region at the beginning of the compressive stress-strain curve NOTE This gradient is not a mo

26、dulus for the material (see Figure 1). The quasi-elastic gradient is optionally measured and it is used to determine the zero point for the compressive strain see Figure 2 a). 3.9 compressive offset stress compressive stress at the plastic compressive strain of 0,2 %, unless otherwise specified or r

27、ecorded NOTE The plastic strain is determined using of the quasi-elastic gradient see Figure 2 a). The compressive 0,2 % offset stress is optionally measured and it can be used as an alternative to the compressive yield strength. 3.10 elastic gradient gradient of the elastic straight lines determine

28、d by elastic loading and unloading between stresses of 70and 20NOTE 1 70and 20correspond to 70 % and 20 %, respectively, of the plateau stress, pl. NOTE 2 The elastic straight line is the secant line obtained from the hysteresis loop which occurs during unloading and subsequent loading (see Figure 1

29、). The elastic gradient represents a porosity-dependent rigidity, not a modulus of the material, and generally changes during the course of compression. The elastic gradient is optionally measured and it is used to determine the zero point for the compressive strain see Figure 2 b). BS ISO 13314:201

30、1ISO 13314:2011(E) ISO 2011 All rights reserved 33.11 compressive proof strength compressive stress at a plastic compressive strain of 1,0 %, unless otherwise specified or recorded NOTE The plastic strain is determined using of the elastic gradient see Figure 2 b). The compressive proof strength is

31、optionally measured and it can be used as an alternative to the compressive yield strength. 21eeeee3(%)eplee= 40= 30 = 20( = 0)= 02070pl130orKey 1 quasi-elastic gradient 2 elastic gradient 3 first maximum compressive strength Figure 1 Stress-strain curve to determine the characteristic values from c

32、ompression testing of porous and cellular metals 12ee (%)e = 0,2 = 012ee2070(%)e = 1 = 0Key 1 quasi-elastic gradient 2 compressive offset stress Key 1 elastic gradient 2 compressive proof strength a) Quasi-elastic gradient and compressive offset stress b) Elastic gradient and compressive proof stren

33、gth Figure 2 Stress-strain curve to determine the optional characteristic values from compression testing of porous and cellular metals BS ISO 13314:2011ISO 13314:2011(E) 4 ISO 2011 All rights reserved4 Principle This test is a method for evaluating compressive properties of porous and cellular meta

34、ls. The compressive test is carried out using a compression test machine with constant crosshead speed. Compressive stress, , and compressive strain, e, are measured from the applied force, F, and displacement of the compressive specimen, respectively. 5 Apparatus 5.1 Test machine, conforming to ISO

35、 7500-1. The machine shall be able to test at constant crosshead speed. Unless otherwise agreed between the parties, a machine of class 1 shall be used for this test. 5.2 Pressing device, consisting of a couple of polished parallel platens, used to apply compressive force to the test specimen. The p

36、latens geometry shall be such that the centres of the upper and lower platens can be aligned to the centre line of the machine casing. Plane-ground, mirror-finished platens with a minimum hardness of at least 60 HRC shall be used. Lubricant may be applied to press surfaces. 5.3 Device for the measur

37、ement of compressive strain, consisting of an extensometer or calculated from the measured displacement between two parallel platens. For the measurement of the elastic gradient and the compressive proof strength, an extensometer mounted on the platens or directly on the respective sample shall be u

38、sed to measure the compressive strain. Alternatively, the measurement may be carried out using an optical extensometer. In the relevant range, the accuracy of the extensometer shall, as a minimum requirement, correspond to class 1 in accordance with ISO 9513. 6 Test specimen 6.1 Geometry Test specim

39、ens which are cylindrical (recommended) or rectangular in cross-section shall be used in the compressive test (see Figure 3). All spatial dimensions of the specimen (W0 and D0in Figure 3) shall be at least 10 times the average pore size, da, and no less than 10 mm, with a sample length to diameter r

40、atio (H0: D0) or sample length to edge length ratio (H0:W0) of between 1 and 2. The sample geometry shall be recorded in the test report. The average pore size (i.e. diameter, in the case of spherical porosity, and the axial and transverse dimensions in the case of non-spherical porosity) shall be m

41、easured in the cut section and recorded in the test report. The type of porosity (i.e. open or closed) shall also be recorded. The pore size distribution shall be checked where necessary in the case of closed-pore metal foams by cutting. The average pore size shall be measured in the cut section. 6.

42、2 Number of test specimens The number of test specimens shall be no less than three and a minimum of five is recommended. In addition, for the optional measurement of elastic gradient, a specimen for a preliminary test providing an initial estimate of the plateau stress is required. 6.3 Sampling of

43、test specimen The test specimen shall be sampled from the material structure under test by cutting, milling, turning, electric discharge machining, etc Under no circumstances shall the material properties be affected by the cutting procedure. BS ISO 13314:2011ISO 13314:2011(E) ISO 2011 All rights re

44、served 5The areas in contact with the platens during the test shall be parallel. The remaining cut surfaces shall be perpendicular to the contact surfaces. Cut surfaces shall have any burrs removed. In the case of foamed metals, the skin, in general, is removed. If specimens with skin are used, this

45、 fact shall be recorded in the test report. W0 10daH0 = W0 2W0FD0 10daH0 = D0 2D0Fa) Rectangular specimen b) Cylindrical specimen Key F force Figure 3 Schematic illustration of test specimen 7 Test procedure 7.1 Test temperature The compressive test shall be carried out at ambient temperature within

46、 the range of 10 C to 35 C, and temperature shall be recorded, if necessary. When temperature control is especially necessary, it shall be kept in the range of (23 5) C. 7.2 Measurement of initial dimensions of test specimen The width, thickness, diameter, etc. of the test specimen shall be measured

47、 to the order of 0,1 mm, followed by calculation of the initial cross-sectional area. The height of the test specimen shall be measured to an accuracy of 0,1 mm. Measurement at a minimum of three measuring points is recommended. 7.3 Test speed The compression tests are conducted at a constant crossh

48、ead speed. The crosshead speed is calculated to obtain an initial compression strain rate of between 103s1and 102s1. The compression speed or the initial strain rate shall be recorded in the test report/record. BS ISO 13314:2011ISO 13314:2011(E) 6 ISO 2011 All rights reserved7.4 General conduct of t

49、est The test specimen shall be placed between the platens of the test machine while allowing the centre line of the test specimen to coincide with the centre line of the upper and lower platens. During the compression test, a force/displacement curve shall be recorded for each sample to determine characteristic values according to their definitions in Clause 3. Data sampling frequency should be at least 30 Hz up to 5 % strain or the strain corresponding to compressiv