1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN ISO 2738:2000 The E
2、uropean Standard EN ISO 2738:1999 has the status of a British Standard ICS 77.160 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Sintered metal materials, excluding hardmetals Permeable sintered metal materials Determination of density, oil content and open porosityThis Briti
3、sh Standard, having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 January 2000 BSI 01-2000 ISBN 0 580 35415 6 BS EN ISO 2738:2000 Amendments issued since publication Amd. No. Date Commen
4、ts National foreword This British Standard is the English language version of EN ISO 2738:1999. It is identical with ISO 2738:1999. It supersedes BS 5600-3-3.2:1988 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee ISE/65, Sintered metal components, whi
5、ch has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate the
6、m in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their correspon
7、ding European publications. The British Standards which implement these international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BS
8、I Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary
9、 of pages This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, page ii, pages 1 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.
10、EN ISO 2738:1999A Referencenumbe r ISO2738:1999 (E) INTERNATIONAL STANDARD ISO 2738 Thirdedition 19991101 Sinteredmetalmaterials,excluding hardmetalsPermeablesinteredmetal materialsDeterminationofdensity,oil contentandopenporosity Matriauxmtalliquesfritts,lexclusiondesmtauxdursMatriaux mtalliquesfri
11、ttspermablesDterminationdelamassevolumique,de lateneurenhuileetdelaporositouverte EN ISO 2738:1999)E(9991:8372OSI ii Foreword ISO (the InternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarri
12、edoutthroughISOtechnical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnongovernmental,in liaisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalEl
13、ectrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtoth ememberbodiesforvoting. PublicationasanInternationalStan
14、dardrequiresapprovalbyatleast75%ofthememberbodiescastingavote. InternationalStandardISO2738waspreparedbyTechnicalCommitte eISO/TC119,Powdermetallurgy , SubcommitteeSC3, Samplingandtestingmethodsforsinteredmetalmaterials(excludinghardmetals) . Thisthirdeditioncancelsandreplacesthesecondedition(ISO273
15、8:1987)whichhasbeentechnicallyrevised. EN ISO 2738:1999DRADNATSLANOITANRETNI OSI )E(9991:8372OSI 1 Sinteredmetalmaterials,excludinghardmetalsPermeable sinteredmetalmaterialsDeterminationofdensity,oilcontent andopenporosity 1Scope ThisinternationalStandardspecifiesmethodsofdeterminingthedensity,oilco
16、ntentandopenporosityof permeablesinteredmetalmaterials. Itappliesinparticulartoporousmetalbearingsandtostructuralpartsproducedbypressingandsinteringmetal powders. 2Normative references Thefollowingnormativedocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsof thisInternat
17、ionalStandard.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyofthese publicationsdonotapply.However,partiestoagreementsbasedonthisInternationalStandardareencouragedto investigatethepossibilityofapplyingthemostrecenteditionsofthenormativedocumentsindicatedbelow.For undatedreferences,thela
18、testeditionofthenormativedocumentreferredtoapplies.MembersofISOandIEC maintainregistersofcurrentlyvalidInternationalStandards. ISO758, LiquidchemicalproductsforindustrialuseDeterminationofdensityat20C. ISO13944, LubricatedmetalpowdermixesDeterminationoflubricantcontentModifiedSoxhletextraction metho
19、d. EN ISO 2738:1999)E(9991:8372OSI OSI 2 3 Symbolsanddesignations Table1Symbolsanddesignations Symbol Designation Unit m 1 Initialmassofthetestpiece g m 2 Massofthetestpieceafteroilextractionanddrying g m 3 Massofthefullyimpregnatedtestpiece g m a Massofthefullyorpartiallyimpregnatedtestpieceplussup
20、portingdevice(for examplesuspensionwire)weighedinair g m w Massofthefullyorpartiallyimpregnatedtestpieceplussupportingdevice(for examplesuspensionwire)weighedinwater g V Volumeofthetestpiece cm 3 r w Densityofthewaterused g/cm 3 r 1 Densityoftheoilinitiallyinthetestpiece a g/cm 3 r 2 Densityoftheimp
21、regnatingoilused a g/cm 3 a Theoildensityisassumedtobeknownor,ifnot,tobedeterminedinaccordancewithISO758. 4 Termsanddefinitions ForthepurposesofthisInternationalStandardthefollowingtermsanddefinitionsapply. 4.1 density thedensityofthetestpiecemaybeexpressedintwoways: 4.1.1 drydensity themass,afterdr
22、ying,dividedbythevolume 4.1.2 fullyimpregnateddensity(wetdensity) thefullyimpregnatedmassdividedbythevolume 4.2 oilcontent theoilcontentofthetestpiecemaybeexpressedintwoways: 4.2.1 percentagebyvolume thevolumeoftheoildividedbythevolumeofthetestpieceandmultipliedby100 4.2.2 percentageofthevolumeofthe
23、openporosity thevolumeoftheoildividedbythevolumeoftheopenporosityandmultipliedby100 4.3 openporosity (ofthetestpiece) theoilcontentafterfullimpregnationdividedbythevolumeofthetestpieceandmultipliedby100expressedasa percentagebyvolume 4.4 volume (ofthetestpiece) totalvolumeincludingthepores EN ISO 27
24、38:1999OSI )E(9991:8372OSI 3 5Test procedures Dependinguponwhichofthepropertiesistobedetermined,someorallofthetestproceduresinclause8are carriedout.Table2showsthetestproceduresthatarecarriedoutforthepropertytobedetermined.Thevalues obtainedforthevariousparametersareinsertedintherespectiveformulaegiv
25、eninclause9toobtainthedesired property. Table2Testprocedures Testprocedure Symbolfor result obtained Propertiestobedetermined Density Oilcontent Open porosity Dry Fully impregnated %( V/V) %of open porosity Initialweighingofthetestpiece(see8.1) m 1 33 Extractionoftheoilcontainedintheporesofthe testp
26、iece(see8.2) 33 3 3 Determinationofthemassofthetestpieceafter oilextractionanddrying(see8.3) m 2 33 3 3 Fullimpregnationofthetestpiecewithanoilof knowndensity(see8.4) 33 3 Determinationofthemassofthefully impregnatedtestpiece(see8.5) m 3 33 3 Determinationofthevolumeofthetestpiece (see8.6) V 333 3 6
27、Equipment 6.1Analyticalbalance, ofsufficientcapacityandaccurateto0,01%. 6.2 Soxhletextractor, withoilsolvent. 6.3Deviceforweighingthetestpieceinairandinliquid NOTE Theliquidisusuallywater(seeFigures1,2and3). 6.4Vessel, largeenoughtoaccommodatethetestpieceandthedevice(6.3)forweighingit,containingdist
28、illedor deionized,andpreferablydegassedwater,with0,05%( V/V)to0,10%( V/V)wettingagentadded. 6.5Apparatusforvacuumimpregnationofthetestpiecewithoil 6.6Impregnationoil, ofknowndensity(seeISO758forthedeterminationofthedensityofliquids). 6.7Thermometer, accurateto 0,5 C. EN ISO 2738:1999)E(9991:8372OSI
29、OSI 4 7Testpiece 7.1 Usuallythetestpieceistestedwhole.Ifthisisnotpossible,thetestpiecemaybecutorbrokenintosmaller partstofacilitatethevariousoperations.Itisoftenmostappropriatetotestonlyacriticalsectionofacomponent. 7.2 Ifthetestpiecehasamasslessthan5ganumberoftestpiecesshallbetestedtogethertoobtain
30、the averagevalue. 7.3 Thesurfaceofthetestpieceshallbefreeofadheringdirt,greaseorotherforeignmaterial. 7.4 Thesurfaceofthetestpieceshallbefreefromsurplusoil.Whenremovinganysuchsurplusoilwithanoil absorbentmaterial,careshallbetakentoavoidremovingoilcontainedinthepores. NOTE Thepresenceofsurplusoilonth
31、esurfaceofthetestpieceismostlikelytooccurafterthefullimpregnation treatment. 8Test procedures 8.1 Determinationoftheinitialmassofthetestpiece Weighthetestpieceintheconditioninwhichitwasreceived,toobtain m 1 . NOTE Ifthetestpieceisknowntocontainnooil,theproceduresdescribedin8.2and8.3areomitted.Inthis
32、case, m 1 is substitutedfor m 2 intheformulaegivenin9.1and9.3. 8.2 Removalofoilfromthetestpiecebysolventextraction Approximately3hofsoakingandabouttensolventchangesarerequiredtoremovetheoilfromtestpiecesof averagedensityandsmallwallthickness.Forthickwallsandhighdensity,upto24haresometimesrequired. N
33、OTE1 TheSoxhletextractorisaconvenientapparatusforsoakingthetestpieceinwarm,freshlydistilledoilsolvent.The distillationratedeterminesthenumberofcyclesandhencethenumberofsolventchangesthatoccur.AsuitableSoxhletuniti s describedinISO13944. Continuetheextractiontoconstantmassafterevaporationofthesolvent
34、leftinthepores. NOTE2 Experiencewillindicatethebestextractiontimeanddistillationratetouse. Drythetestpiecetoconstantmass(i.e.untilthereductioninmassproducedbythelastextractiondoesnotexceed 0,01%atatemperatureof20 Cabovetheboilingpointofthesolvent)thencoolinadesiccatorandweigh. Choosethesolventsothat
35、completedissolutionoftheoilinquestionisensured.Thisrequirementshallbetested forseparately.Thesolventusedshallbestatedinthetestreport. Forpracticalcontrolpurposes,othermethodsforremovingtheoilmaybeused(suchasheatingwellbelow sinteringtemperaturesinaprotectiveatmosphere).Incasesofdispute,themodifiedSo
36、xhletextractionmethod shallbethereferencemethod(seeISO13944). 8.3 Determinationofthemassofthedriedtestpiece Weighthetestpieceaftersolventextractionanddryingtoobtain m 2 . EN ISO 2738:1999OSI )E(9991:8372OSI 5 8.4 Impregnationwithoilandsurfacecoating 8.4.1 Fullimpregnation(fordeterminationoftheopenpo
37、rosity) Submergethetestpieceinoil,containedinanysuitablevesselcapableofwithstandingavacuum.Reducethe pressureonthesurfaceoftheoilto70kPamaximum. Continuethevacuumtreatmentuntilnofurtherbubblesappearonthesurfaceoftheoil. Restorethepressureinthevacuumchambertothatoftheambientatmosphere.Allowthetestpie
38、cetoremain submergedintheoilforaperiodof10min. NOTE1 Forthemajorityofporousmetalsasinglevacuumtreatmentissufficientforensuringfullimpregnation.Insome casesasecondvacuumtreatmentisnecessarytoachievefullimpregnation.Thiscanbeestablishedbyreducingthepressure asecondtime,andifnofurtherairbubblesappear,i
39、tcanbesafelyassumedthatthefirsttreatmenthasachievedfull impregnation. Theoilshallbecompletelyimmisciblewithwaterandshallwettheporousmetal. NOTE2 Generallytheoilshallhaveaviscosityat40 Cofbetween22mm 2 /sand68mm 2 /s 1) whichcorrespondsto ISOVG22toVG68asspecifiedinISO3448.Withalowviscosityoil,impregn
40、ationisfasterthanwithahighviscosityoil. Removethetestpiecefromtheoil,allowtodrainandremovethesurplussurfaceoilasdescribedin7.4. 8.4.2 Partialimpregnation(suitablefordeterminationofthevolume) Therequirementsoftheoilarethesameasstatedin8.4.1. Submergethetestpieceinhotoil(70 C 10 C)untilnofurtherairbub
41、blesappear.Coolthetestpiecetoroom temperaturewhilststillsubmergedinoilbyremovingitfromthehotoilandquicklytransferringittocoldoil.Remove thecooledtestpiecefromthecoldoil,allowtodrainandremovethesurplussurfaceoilasdescribedin7.4. 8.4.3 Surfacecoatingmethods(suitablefordeterminationofthevolume) Coatthe
42、poroussurfaceofthetestpiecewithafilmthat,bymeansofsurfacetension,preventsthewaterfrom enteringthepores. Thefollowingtechniqueshavebeenfoundtobesuitableforparticulartypesofporousmetal.However,beforeany areused,theeffectivenessofthetechniquewithrespecttothetypeandshapeofporousmetalshallfirstbe establi
43、shed. 8.4.3.1Petroleum jelly Smearthesurfaceofthetestpiecewithpetroleumjellyandremoveanyexcess. 8.4.3.2Silicones Manysiliconefluidsproducesurfacefilmswhicharenotwettedbywater.Dipthetestpieceintoeitherthesilicone fluidoradilutesolutionofthesiliconefluidinasuitablesolventanddrytoconstantmass. 8.4.3.3Paraffin wax Dipthetestpieceina5%solutionofparaffinwaxinasuitablesolventanddrytoconstantmass. 8.5 Determinationofthemassofthefullyimpregnatedtestpiece Weighthetestpieceafterfulloilimpregnationtoobtain m 3 .
