納米晶金屬銀的力學(xué)行為與形變機(jī)制研究.pdf

1、浙江大學(xué)碩士學(xué)位論文納米晶金屬銀的力學(xué)行為與形變機(jī)制研究姓名：林良道申請學(xué)位級別：碩士專業(yè)：材料物理與化學(xué)指導(dǎo)教師：吳希俊2002.3.1浙江大學(xué)碩士學(xué)位論文ABSTRACTThetensileandcompressionexperimentonbulknanocrystallineAgpreparedbyIGCmethodwascarriedonMT810witlldifferentgrainsizesandZwick10TN2SMa

2、chineatdifferentstrainratesundernormaltemperaturerespectivelyThestainratesensitivitymwasfoundtobe0025，whichWasextremelylowerthantheordinaryvaluesAlsotheworkhardeningexponentisverylowUnderthecarefulretrospectionandanalysi

3、sonthepreviousandrecentexperimentSaboutmechanicalbehaviorofnanocrystallinemetalsperformedbyalmostmaininvestigators，thedislocationandatomicdiffusionisbelievedtocontributehardlytothedeformationofnanocrystallinealloyandamod

4、elbasedonthermalactivationprocessWasappliedtofittheexperimentaldataofnanocrystallineAgTheapparentactivationvolumecalculatedbythemodelisabout2500A3，whichwastentimeslargerthanthatofusualamorphousalloyandWasatthesanlerangeo

5、ftheamorphouspolymerThemodelshowsthemaindeformationmechanismofnanocrystallineAgisgrainboundarysliding，whichinsomeextentdeclaresthesimilarformsofequationwithamorphousalloysWimtheananlysistotheHREMofnanocrystallineAgthedis

6、crepancyoftheapparentactivationvolumebetweenthenanocrystallineAgandamorphousalloysisinterpretedbythelossofatomsparticipatingingrainboundaryslidingwithoutenoughreconstructionbythemovementofatomsunderthelowtemperatureToexp

7、laintheinverseHallPetchrelationinnanocrystallinemetals，ageometricmodelismade，whichassurnesthatthegrainsaresphericalcrystals，andthethickofgrainboundaryisconsiderablecomparedwiththemicrocrystallinemetalsThismodelalsothrows

8、alightontheabilityofgeRinghighstrengthofnanocrystallinemetalsthroughamorphousmetals’crystallization【KeywordInanoerystallineAg；mechanicalbehavior；deformationmechanism；grainboundarysliding；strainratesensitivity；activationv