1、BS ISO 20808:2016Fine ceramics (advancedceramics, advanced technicalceramics) Determinationof friction and wearcharacteristics of monolithicceramics by ball-on-discmethodBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 20808:2016 BRITISH STANDARDNational forewo
2、rdThis British Standard is the UK implementation of ISO 20808:2016.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 on request to its secretary.This publication does no
3、t purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 90391 5ICS 81.060.30Compliance with a British Standard cannot confer immunity fromlegal oblig
4、ations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 July 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 20808:2016 ISO 2016Fine ceramics (advanced ceramics, advanced technical ceramics) Determinatio
5、n of friction and wear characteristics of monolithic ceramics by ball-on-disc methodCramiques techniques Dtermination des caractristiques de frottement et dusure des cramiques monolithiques par la mthode “bille sur disque”INTERNATIONAL STANDARDISO20808Second edition2016-07-15Reference numberISO 2080
6、8:2016(E)BS ISO 20808:2016ISO 20808:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mec
7、hanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, Sw
8、itzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 20808:2016ISO 20808:2016(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Significance and use 25 Test materials and specimen preparation . 25.1 Materials . 25.2 Ball specimen . 35.3 Disc
9、specimen 36 Apparatus . 37 Testing procedure . 47.1 Determination of specimen density 47.2 Treatment of specimen before test 47.3 Measurement of mass before test . 47.4 Preparation of wear test . 47.5 Testing conditions 47.6 Measurement of friction force . 57.7 Measurement of mass after test . 57.8
10、Measurement of wear scar on ball specimen . 57.9 Measurement of wear track on disc specimen 57.10 Number of test repeats 58 Calculation of test results 68.1 Specific wear rate of ball specimen . 68.1.1 Specific wear rate according to wear volume . 68.1.2 Specific wear rate according to mass loss 88.
11、2 Specific wear rate of disc specimen 88.2.1 Specific wear rate according to wear volume . 88.2.2 Specific wear rate according to mass loss 98.3 Coefficient of friction . 98.4 Rounding off of numerical values . 99 Test report 10Bibliography .11 ISO 2016 All rights reserved iiiContents PageBS ISO 208
12、08:2016ISO 20808:2016(E)ForewordISO (the International Organization for Standardization) 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
13、a subject for which a technical committee has been established has the right 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 Commissi
14、on (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents shoul
15、d be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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 iden
16、tifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the conveni
17、ence of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the
18、 following URL: www.iso.org/iso/foreword.html.The committee responsible for this document is ISO/TC 206, Fine ceramics.This second edition cancels and replaces the first edition (ISO 20808:2004), which has been technically revised.iv ISO 2016 All rights reservedBS ISO 20808:2016INTERNATIONAL STANDAR
19、D ISO 20808:2016(E)Fine ceramics (advanced ceramics, advanced technical ceramics) Determination of friction and wear characteristics of monolithic ceramics by ball-on-disc method1 ScopeThis document specifies a procedure for and provides guidance on the determination of the coefficient of friction a
20、nd the specific wear rate for monolithic ceramics. In this method, the materials are tested in pairs, in a ball-on-disc configuration, under dry, non-abrasive conditions.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitu
21、tes requirements 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 1101, Geometrical product specifications (GPS) Geometrical tolerancing Tolerances of form, orientation
22、, location and run-outISO 3274, Geometrical Product Specifications (GPS) Surface texture: Profile method Nominal characteristics of contact (stylus) instrumentsISO 3611, Geometrical product specifications (GPS) Dimensional measuring equipment: Micrometers for external measurements Design and metrolo
23、gical characteristicsISO 4287, Geometrical Product Specifications (GPS) Surface texture: Profile method Terms, definitions and surface texture parametersISO 13385 (all parts), Geometrical product specifications (GPS) Dimensional measuring equipmentISO 80000-1, Quantities and units Part 1: GeneralISO
24、/IEC 17025, General requirements for the competence of testing and calibration laboratories3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Elec
25、tropedia: available at http:/www.electropedia.org ISO Online browsing platform: available at http:/www.iso.org/obp3.1wearalteration of a solid surface by progressive loss or progressive displacement of material due to relative motion between that surface and a contacting substance or substances3.2we
26、ar testmethod of evaluating the friction and wear performance of materials in sliding contact ISO 2016 All rights reserved 1BS ISO 20808:2016ISO 20808:2016(E)3.3ball-on-disc methodwear test method in which the sliding contact is brought about by pushing a ball specimen on to a rotating disc specimen
27、 under a constant load3.4friction forceresisting force tangential to the interface between two bodies when, under the action of an external force, one body moves or tends to move relative to the other3.5coefficient of frictiondimensionless ratio of the friction force between the two bodies, Ff, to t
28、he normal force, Fp, pressing these bodies together =FFfp3.6specific wear rateWsrate of material removal by wear defined as the quotient of wear volume, V, and the product of normal force, FP, and sliding distance, LWVFLPs=()4 Significance and useThis document gives guidance on conducting a sliding
29、friction and wear test in a ball-on-disc configuration. It shall be used to determine the wear resistance and friction generated in uniaxial sliding contacts between ceramics.It should be noted that there are many parameters in sliding contact that affect the magnitude of friction and wear. The aim
30、of performing any wear test is to simulate, as closely as possible, the conditions that occur in the real application. As the deviation between the test conditions and the application conditions becomes larger, the test results become less relevant. To add credence to the test results, the appearanc
31、e of the worn surfaces from the test samples shall be compared with the appearance of the worn surface from the actual worn component in order to ensure that similar wear mechanisms have taken place in each case.The recommended test conditions suggested in this document shall be used when the applic
32、ation conditions are not well defined but general comparison among materials is required.5 Test materials and specimen preparation5.1 MaterialsThis test method can be applied to a variety of materials. The only requirement is that ball and disc specimens having the dimensions specified below can be
33、prepared, and that they shall withstand the stresses imposed during the testing without failure or excessive flexure. In principle, the ball and disc specimen should be from the same material, but ball and disc specimens from different materials can also be tested by this method. Any pertinent detai
34、ls of the materials such as their dimensions, surface finish, material type, composition, microstructure and processing treatments shall be reported.2 ISO 2016 All rights reservedBS ISO 20808:2016ISO 20808:2016(E)5.2 Ball specimenThe ball specimen shall be a true sphere of more than 5 mm diameter, o
35、r a straight rod whose end part is machined to a spherical cap. The recommended diameter of the sphere is 10 mm. The surface roughness of the specimen shall be not more than 0,1 m Raas specified in ISO 4287.5.3 Disc specimenThe disc specimen shall be more than 3 mm in thickness and be large enough t
36、o enable the testing surface to contain a sliding circle of more than 30 mm diameter. The surfaces of the disc shall be flat and parallel to within 0,02 mm as specified in ISO 1101. The roughness of the test surface shall be not more than 0,1 m Raas specified in ISO 4287.6 Apparatus6.1 Ball-on-disc
37、method testing apparatus.The testing apparatus shall consist of the following: the disc holder, for securing a disc specimen; the drive system for rotating the disc; the ball holder for gripping a ball specimen; the loading mechanism for pushing the ball specimen on to the disc specimen; the equipme
38、nt for measuring the friction force and the linear wear; the equipment for controlling the testing atmosphere; the ancillary devices for the above.a) The disc holder shall rotate in a horizontal or vertical plane. The eccentricity of rotating axis shall be less than 0,02 mm and the fluctuation at th
39、e contact point in the direction perpendicular to the disc shall be less than 0,05 mm.b) The drive system shall be capable of giving a controllable sliding speed that is stable under the influence of the friction forces that are generated. The drive system shall be fitted with a revolution counter o
40、r equivalent device.c) The ball holder shall firmly grip the ball specimen and have a high rigidity with respect to the stress generated at the contact point with the disc specimen.d) The loading mechanism shall apply a controlled load to the ball holder directly or through a lever-arm device with a
41、ttached weight, or by a hydraulic or pneumatic system.e) The friction force shall be measured by means of mechanisms, such as a load cell, distortion of a leaf spring or measurement of rotational torque. The measurement should not affect the frictional condition. The accuracy of friction measurement
42、 shall be 1 % or better of the applied load. A device for measuring the linear wear is optional, but when provided it should have a sensitivity of 2,5 m or better.f) The testing atmosphere shall be controlled to within 2 C of the set temperature and the relative humidity to (50 10) %. Alternatively,
43、 the testing apparatus itself can be placed in a room with conditions controlled to these limits.g) If the specification of testing apparatus is different from the above, it shall be described in the test report. ISO 2016 All rights reserved 3BS ISO 20808:2016ISO 20808:2016(E)6.2 Balance, capable of
44、 measuring the mass of the specimen to the nearest 0,01 mg.6.3 Micrometer calliper, capable of measuring as specified in ISO 3611 or equivalent or better.6.4 Vernier calliper, having a resolution of 0,05 mm as specified in ISO 13385 (all parts) or equivalent or better.6.5 Micrometer microscope, capa
45、ble of reading to the nearest 0,01 mm.6.6 Contact stylus profilometer, as specified in ISO 3274 or at least equal thereto in precision.7 Testing procedure7.1 Determination of specimen densityMeasure the diameter of the ball specimen and the diameter and thickness of the disc specimen using a microme
46、ter calliper (6.3), Vernier calliper (6.4) or equivalent, and calculate the density of the specimen from the mass measured in accordance with 7.3. The density value measured by another method having equivalent or superior precision can also be used, e.g. density determination in accordance with ISO
47、18754.7.2 Treatment of specimen before testWash specimens ultrasonically in high purity acetone for 10 min or longer, with the testing surface downwards in the case of the disc specimen. Without allowing them to dry, the specimens should be rinsed with high purity hexane and then dried for 30 min or
48、 longer in an oven set at 120 C. Acetone and/or hexane can be replaced with other solvents or deionized water as long as clean specimen surfaces are produced at the end of the procedure. The specimens shall be stored in the same atmosphere as that used for the wear testing apparatus until required.7
49、.3 Measurement of mass before testMeasure the mass of each specimen by weighing it with a balance (6.2) immediately before the wear test.7.4 Preparation of wear testClamp the ball and disc specimen firmly in position in their respective holders and bring them gently into contact, then apply the set load. After the testing atmosphere has stabilized for at least 30 min, start the test by rotating the disc at the set condition.7.5 Testing conditionsRecommended test conditions are listed below, but can be chang
