镍钛形状记忆合金在局部包套压缩下的塑性屈服.pdf

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1、Availableonlineatwww．sciencedirect．corn一Transactionsof锄鼯ScienceDirectNonferrousMetalsSocietyofChinaELERPressTrans．NonferrousMet．Soc．China23(2013)2905—2913WWW．tnmsc．cnPlasticyieldingofNiTishapememoryalloyunderlocalcanningcompressionShu．yongJIANG，LiHU，Ya

2、．nanZHAO，Yan—qiuZHANG，Yu．1ongLIANG1．IndustrialTrainingCentre，HarbinEngineeringUniversity,Harbin150001，China；2．CollegeofMaterialsScienceandChemicalEngineering，HarbinEngineeringUniversity,Harbin150001，ChinaReceived12September2012；accepted7November2012Abs

3、tract：Asanewattempt．1oca1canningcompressionwasappliedinordertoimplementlargeplasticdeformationofnickel-titaniumshapememo~alloy(NiTiSMA)atroomtemperature．Theplasticmechanicsofloca1canningcompressionofNiTiSMAwasanalyzedaccordingtotheslabmethodasthewel1as

4、plasticyieldcriterion．Transmissionelectronmicroscopy(TEM1，highresolutiontransmissionelectronmicroscopy(HRTEM)andscanningelectronmicroscopy(SEM1wereusedtostudythemicrostructuralevolutionaswel1asdeformationbehaviorofNiTisamplesunderloca1canningcompressio

5、n．Increasingthehydrostaticpressurewiththeincreaseintheouterdiametersofthestee1cansisresponsibleforsuppressingtheinitiationandgrowthofthemicro—cracks．whichcontributestoenhancingtheplasticityofNiTiSMAandavoidingtheoccurrenceofbrittlefracture．Plasticdefor

6、mationofNiTiSMAunderathree—dimensionalcompressivestressstatemeetsvon—Misesyieldcriterionatthetruestrainsrangingfromabout0．15tO0．50．whileinthecaseof1argerplasticstrain．von—MisesyieldcriterionisunabletobemetsincetheamorphousphasearisesinthedeformedNiTisa

7、mple．Keywords：NiTialloy；shapememowalloy；yieldcriterion；plasticdeformation；plasticmechanicsthecaseofannealing，whichcausesNiTiSMAtopossess1Introductionanultimatetensilestrengthof2650MPaatroomtemperatureandthemaximumelongationofmorethanTheremarkableattrac

8、tivenessofnickel-titanium200％at500。C[10]．DELVILLEetal[11]appliedheatshapememoryalloy(NiTiSMA、comesfromitsshapetreatmentbypulsedelectriccurrentforobtainingmemoryeffectaswellassuperelasticity[11．ChemicalnanocrgstallizationofamorphousNiTiw