鋁合金連接件腐蝕疲勞性能的研究.pdf

1、東北大學碩士學位論文鋁合金連接件腐蝕疲勞性能的研究姓名：張正貴申請學位級別：碩士專業(yè)：機械設計及理論指導教師：黃雨華2000.7.1東北人學碩J：論文ABSTRACTABSTRACTRivetedjoints，whicharecommoncomponentsinmachine，areoftensufferedfromnotonlyfatigueloadbutalsoenvironmentalcorrosionEspecially，som

2、emachines，whicharebeinginmilitaryservicealongthecoast，SUffermoreseverecorrosionItwasfoundthatinteractionbetweencorrosionandmechanicalforcegreatlyreducedCFlifeofcomponentswhichmakefacilitiesfaliedinadvanceThecorrosionfati

3、guefCF)behaviorofLY12CZaluminumalloyrivetedlap—splicejointswithcoatingwerestudiedin35％NaCIsolutionTestswereconductedin35％sodiumchloridesolutionatdifferenttemperatureswithdifferentpreimmersiontimeThecrackinitiationsitesco

4、rrosionmicrographandthefractographwereexaminedbySEMTheresultsshowedthattheimmersedtimehadagreateffectontheCFlifethemoretheimmersiontimethe10wertheCFlireTheCFlifedisplayedanexponentialfunctionoftimeSEMobservationsalsoindi

5、catedthatthemorethepreimmersiontimethemoreseverethepittingandintergranularcorrosionItwasalsofoundthatCFIifcoftherivetedspecimenwithoutpre—immersionwaslongerthanthatinairattheroomtemperatureunderboththerelativelyhighstres

6、samplitudeandtherelativelylowstressamplitudeconditionsHowever，thisresultgreatlydependedontheexperimentalconditionsCFtestsathightemperature，lowpHvalueandpre—immersionconditionsdidn’tshowlongerCFlivesascomparedtothatinairT

7、helowpHvalue，thehightemperaturewillreduceCFlifeandCFlifeiSanexponentialfunctionoftemperatureSEMobservationsshowedthatthedegreeofcorrosionwashigherundertheseconditionsTheexperimentsunderbothrelativelyhigherandlowerstressa

8、mplitudesshowedthattheeffectofcorrosiononCFIireatIOWstressamplitudewasmoreevidentthanthatatrelativelyhigherstressamplitudeTheresultsindicatedthatcorrosionfactorsplaymoreimportantrolesatrelativelylowstressamplitudethantha