简介:Animprovedthree-dimensional(3-D)experimentalvisualizationmethodologyispresentedforevaluatingthefracturemechanismsofferriticstainlesssteelsbyin-situtensiletestingwithanenvironmentalscanningelectronmicroscope(ESEM).Thesamplesweremachinedwitharadialnotchedshapeandaslopedsurface.Bothplanarsurfacedeformationandslopingsurfacedeformation-inducedmicrovoidswereobservedduringdynamictensionexperiments,whereagreateramountofinformationcouldbeobtainedfromtheslopingsurface.Theresultsshowedthatmicrovoidsformedatthegrainboundariesofhighlyelongatedlargegrains.Themicrovoidsnucleatedintheseverelydeformedregionsgrewnearlyparalleltothetensileaxis,predominantlyalongthegrainboundaries.Themicrovoidsnucleatedattheinterfaceofparticlesandthematrixdidnotpropagateduetothehighplasticityofthematrix.Thelargemicrovoidspropagatedandshowedazigzagshapealongthegrainboundanes,seeminglyaconsequenceofthefractureoftheslipbandscausedbydislocationpile-ups.Thefinalfailuretookplaceduetothereductionoftheload-bearingarea
简介:Anexperimentalapparatusandanumericalsimulationmodelwerebuiltforinvestigatingthedentresistanceoflightweightthree-piececans.Thedentresistanceofrawmaterials0.19mmT4and0.17mmDR7Mwascompared.Itwasfoundthatwhenthethicknessreducedfrom0.19to0.17mm,thedentresistancebecameabout80%ofthatbeforethinning.Thisprovidesaguidanceforthecontinuousthinningofthree-piececans.
简介:Afacilecatalysis-freemethodwasutilizedtosynthesizefunctionalneodymiumhexaboride(NdB6)nanowiresofsinglecrystalusingNdpowdersandBCl3asstartingmaterials.TheXRDpatternconfirmedthatasinglephaseNdB6couldbeobtained.Raman-spectraelucidatedtheactivevibrationalmodesofthehexaborides.TheTEMimagesclearlyshowedthatthehexaboridesweresubmicroninsizewithacubicmorphology.Thefieldemissionoftheseone-dimensionalNdB6nanowiresshowedalowfieldemissionturn-on(5.55V/μmatacurrentdensityof10μA/cm2),andhighcurrentdensitywithafieldenhancementfactorof1037.TheemissioncurrentdensityandtheelectricfieldfollowedtheFowler-Nordheim(F-N)relationship.Thegoodperformanceforfieldemissionwasattributedtothesingle-crystallinestructureandthenanowiregeometry.
简介:Baosteel's5mheavyplateplantwassuccessfullytestedonMarch1,2005.Sincethen,theHeavyPlatePlantofBaosteel(hereinafterreferredtoas'theplant')hasbeenencouragingitsemployeestostudyandtracetheadvancedheavyplatetechnologies,tryingtofindouttherulesofheavyplateproductionanditsqualitycontrol.TheplanthasgraduallymasteredthismodernheavyplateplantandensuredthatBaosteel'sproductionofheavyplatesgrewyearbyyear,with1.41Mtproductputinstoragein2007.Theplanthasfocusedondevelopingnewtechnologiesandproducts,meanwhileenhancingitscapacity.Ithasproducedaseriesofplateproducts,whichcanbeusedinmanufacturingshiphulls,pipelines,bridges,buildings,boilersandpressurevessels.