【英文标准名称】:StandardPracticeforHeatAgingofPlasticsWithoutLoad
【原文标准名称】:通用的玻璃制品齿轮油氧化和热稳定特性的标准实施规程
【标准号】:ASTMD3045-1992(2010)
【标准状态】:现行
【国别】:美国
【发布日期】:1992
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D20.50
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:aging;exposure;heat;heat-aging;thermal-aging;Acceleratedaging/testing--plastics;Heataging;Heatingtests--plastics;Oxidationtesting--plastics;Thermalanalysis(TA)--plastics
【摘要】:Theuseofthispracticepresupposesthatthefailurecriteriaselectedtoevaluatematerials(thatis,thepropertyorpropertiesbeingmeasuredasafunctionofexposuretime)andthedurationoftheexposurecanbeshowntorelatetotheintendeduseofthematerials.Plasticmaterialsexposedtoheatmaybesubjecttomanytypesofphysicalandchemicalchanges.Theseverityoftheexposuresinbothtimeandtemperaturedeterminestheextentandtypeofchangethattakesplace.Aplasticmaterialisnotnecessarilydegradedbyexposuretoelevatedtemperatures,butmaybeunchangedorimproved.However,extendedperiodsofexposureofplasticstoelevatedtemperatureswillgenerallycausesomedegradation,withprogressivechangeinphysicalproperties.Generally,shortexposuresatelevatedtemperaturesmaydriveoutvolatilessuchasmoisture,solvents,orplasticizers,relievemoldingstresses,advancethecureofthermosets,andmaycausesomechangeincoloroftheplasticorcoloringagent,orboth.Normally,additionalshrinkageshouldbeexpectedwithlossofvolatilesoradvanceinpolymerization.Someplasticmaterialsmaybecomebrittleduetolossofplasticizersafterexposureatelevatedtemperatures.Othertypesofplasticsmaybecomesoftandsticky,eitherduetosorptionofvolatilizedplasticizerorduetobreakdownofthepolymer.Thedegreeofchangeobservedwilldependonthepropertymeasured.Differentproperties,mechanicalorelectrical,maynotchangeatthesamerate.Forinstance,thearcresistanceofthermosettingcompoundsimprovesuptothecarbonizationpointofthematerial.Mechanicalproperties,suchasflexuralproperties,aresensitivetoheatdegradationandmaychangeatamorerapidrate.Ultimatepropertiessuchasstrengthorelongationaremoresensitivetodegradationthanbulkpropertiessuchasmodulus,inmostcases.Effectsofexposuremaybequitevariable,especiallywhenspecimensareexposedforlongintervalsoftime.Factorsthataffectthereproducibilityofdataarethedegreeoftemperaturecontroloftheenclosure,humidityoftheoven,airvelocityoverthespecimen,andperiodofexposure.Errorsinexposurearecumulativewithtime.Certainmaterialsaresusceptibletodegradationduetotheinfluenceofhumidityinlong-termheatresistancetests.Materialssusceptibletohydrolysismayundergodegradationwhensubjectedtolong-termheatresistancetests.Itisnottobeinferredthatcomparativematerialrankingisundesirableorunworkable.Onthecontrary,thispracticeisdesignedtoprovidedatawhichcanbeusedforsuchcomparativepurposes.However,thedataobtainedfromthispractice,sinceitdoesnotaccountfortheinfluenceofstressorenvironmentthatisinvolvedinmostreallifeapplications,mustbeusedcautiouslybythedesigner,whomustinevitablymakematerialchoicesusingadditionaldatasuchascreepandcreeprupturethatareconsistentwiththerequirementsofhisspecificapplication.Itispossibleformanytemperatureindexestoexist,infact,oneforeachfailurecriterion.Therefore,foranyapplicationofthetemperatureindextobevalid,thethermalagingprogrammustduplicatetheintendedexposureconditionsoftheendproduct.Ifthematerialisstressedintheendproductinamannernotevaluatedintheagingprogram,thetemperatureindexthusderivedisnotapplicabletotheuseofthematerialinthatproduct.TherecanbeverylargeerrorswhenArrheniusplotsorequationsbasedondatafromexperimentsataseriesoftemperaturesareusedtoestimatetimetoproduceadefinedpropertychangeatsomelowertemperature.Thisestimateoftimetoproducethepropertychangeorx201C;failurex201D;atthelowertemperatureisoftencalledthex201C;【英文标准名称】:Sanitaryware.Controlofwatertightnessandwaterweighabsorbedbysanitaryceramicware.Testmethods.
【原文标准名称】:卫生设备.卫生设备陶瓷防水密封性和吸水性能控制.试验方法
【标准号】:NFD14-512-1986
【标准状态】:现行
【国别】:法国
【发布日期】:1986-09-01
【实施或试行日期】:1986-09-20
【发布单位】:法国标准化协会(AFNOR)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:设备;试验;检验;陶瓷;上釉陶瓷;吸附水;吸水率;不透水性试验;图表;卫生器具;不透水性;釉层;重量测量;设备容纳设施
【英文主题词】:
【摘要】:
【中国标准分类号】:Q31
【国际标准分类号】:91_140_70
【页数】:7P;A4
【正文语种】:其他