ADC12铸造铝合金齿轮箱开裂原因分析_涂建国

40420154HEATTＲEATMENTOFMETALSVol.40No.4April2015ADC12518117、、ADC12。βAl9Fe2Si2。TG115A0254-6051201504-0198-03FracturefailureanalysisofADC12aluminumalloygearboxTuJianguoZhouSuzhenSiYachunHuHailiShenzhenCenterforAnalysisandMeasurementofMaterialSurfaceShenzhenGuangdong518117ChinaAbstractThereasonforfractureofADC12aluminumalloygearboxwasanalyzedbymeansofSEMobservationchemicalcompositionhardnessandmetallographicexamination．TheresultsshowthattheinsideofgearboxhasmoreacicularbetaAl9Fe2Si2brittlephaseandrelativelyconcentrateddistributionofmicroporosityporewhichincreasethebrittlenessofdiecastingaluminumalloyandreducethebearingstrengthofmaterials．Thecombinationofexternalloadandassemblingpositioningpinstressleadtoearlyfatiguefractureofgearboxparts．Keywordsaluminumalloygearboxfatiguefracturefailureanalysis2014-10-081985—[e-mail]10．13251/j．issn．0254-6051．2015．04．047。、、。ADC12。36757。700～740℃—675±10℃—。ADC12%9．6～12Si、1．5～3．5Cu、≤1．3Fe、≤0．5Mn、≤0．3Mg、≤0．5Ni、≤1．0Zn、≤0．2Sn≥228MPa≥154MPa≥1．4%≥74．1HBW。。11．11a、31b1c。1．2LeicaDMLM2a。α+Siα2b。2c。βAl9Fe2Si22d。1．3JEOLJSM-6460LV3a3b+3c3d。+3e。3f、、、、、、、、、、4ADC121991abcFig．1Macroscopicpicturesofthegearboxafracturegearboxbfractureappearanceofgearboxcartificialfractureappearance2abcdFig．2Microstructureofthefracturegearboxalocalloosedefectsbmicrostructurecinhomogeneousmicrostructuredblackstripandblockmicrostructure、、、、Al9Fe2Si2。1．492．2、93．5、95．1HBW94HBWJISH5302—2006《》ADC12。1．51JISH5302—2006ADC12。1%Table1Chemicalcompositionofthefracturegearboxmassfraction%SiCuFeMnMgNiZnTiSnPb11．382．010．700．120．130．0480．990．0230．0210．065ADC129．60～12．01．5～3．5≤1．3≤0．5≤0．3≤0．5≤1．0≤0．3≤0．5≤0．222．1α+Siα200403SEM+EDSabcdefEDSFig．3SEMandEDSmicroscopicappearanceofthefracturegearboxacrackssourceareabcrackspropagationareacinstantaneousfractureareadinsidewallofholeeartificialfracturefEDSpatternβAl9Fe2Si21。2．2+2-3。、、、、βAl9Fe2Si2SiAl4。31290～300℃2～4h。。2≤0．5%。0．7%wMn∶wFe=0．7～0．8。3。ADC12。1．ZL101AJ．200529548-49．WuChaoqunZhangMingTanCanrong．FracturefailureanalysisofcastedZL101AaluminiumwheelJ．HotWorkingTechnology200529548-49．2．J．2005273358-370．ZhongQunpengZhaoZihuaZhangZheng．DevelopmentoffractographyandresearchoffracturemicromechanismJ．JournalofMechanicalStrength2005273358-370．3．J．20083310114-118．WangWeifuWangMaocaiSunFengjiuetal．Failureanalysisofaluminumalloyscroll-caseonintensifierpumpusedinaero-engineJ．HeatTreatmentofMetals20083310114-118．4．J．200631893-95．GongLeiFuGeyan．FailureanalysisofparietalcrackinginscavengingpumpmadeofdiecastingaluminumalloyJ．HeatTreatmentofMetals200631893-95．