鐵磁形狀記憶合金Ni-,2-MnGa的力-磁耦合行為實驗研究.pdf

1、蘭州大學(xué)碩士學(xué)位論文鐵磁形狀記憶合金NiMnGa的力磁耦合行為實驗研究姓名：何寶明申請學(xué)位級別：碩士專業(yè)：力學(xué)工程力學(xué)指導(dǎo)教師：王省哲20080501蘭州大學(xué)碩士學(xué)位論文AbstractFerromagneticshapememoryalloys(FSMAs)aleanowtypeoffunctionalmaterial，whichexhibitmanyoutstandingadvantagessuchaslfi【ghferromagn

2、etism，largemagnetostrain，thermoelasticandmagneticshapememoryeffectFerromagneticshapememoryalloysarepotentialinactuatorsapplicationbecauseitsresponsefrequencyisashighaspiezoelectricmaterials，strainstressoutputcanbecompare

3、dwiththermalshapememoryalloysInthispaperexperiment011magnetomechanicalcouplingbehaviorofNi2MnGaundermagneticfieldandstressaresystemicallystudiedFirstlythemicro—mechanismandbehaviorofmagnetostrainofsinglecrystalNi“MnOafer

4、romagneticshapememoryalloyshasbeenexpatiatedbasedonreferencesNi2MnGaexhibitspseudoelasticbehavior，whenthematerialisappliedatlowmagneticfield(1H3kOe)，thepseudoelasticbehaviorispartialNi2MnGasinglecrystal，becauseofhighlypr

5、eferredtwinvariants，canproducehugemagnetostrainundermagneticfield，magnetomechanicalcouplingisstrongSecondlytheeffectsofappliedaxialprecompressivestl“eSSCSandmagneticfieldsOHthemagnetomechanicalcharacteristicsofferromagne

6、ticshapememoryalloysNis2Mu27Ga21andNis4Mn25Ga21polycrystallinesampleshavebeenstudiedexperimentallywithselfdesignedequipmentThemagnetizationcBrvesandmagnetizationhysteresisloopsmeasuredalongaxialdirectionofthetwokindsofsa

7、mpleswithdifferentinclinationanglesofappliedmagneticfieldsandaxialprecompressivestressesworeobtainedaswellasstress—strainloopsandmagnetostrainc11lVesTheexperimentalresultsshowedthatthesaturationmagnetizationvaluesmeasure

8、dalongaxialdirectionofthesamplesdecreasewiththeinclinationangleofappliedmagneticfieldsincreasesTheprecompressivestresseshave110obviouseffectonthemagnetizationcurveandmagnetizationhysteresisloopTheappliedmagneticfieldswit