简介：钻石粒子增强了铝硅矩阵composites，作为艾尔(Si)/diamondcomposites缩短了，被制作由压榨扔。微观结构和composites的机械性质上的Si内容的效果被调查。机械性质被发现monotonically增加，Si内容增加直到7.0?wt%。Al-7.0?wt%Si/diamond合成展览78的张力的力量?MPa，230的弯曲力量?426的MPa，和压缩力量?MPa。Al-Si最容易溶解的阶段被显示紧与艾尔矩阵和钻石粒子连接，它为在艾尔(Si)/diamondcomposites的机械性质的改进负责。

简介：Inordertoinvestigatetheelectromagneticshieldingeffectiveness(SE)andabsorbingpropertiesoffiberreinforcedconcrete,steelfiber,carbonfiberandsyntheticpolyvinylalcohol(PVA)fiberreinforcedconcretewereresearched.Theresultsshowthatwiththeincreaseoffibervolumefraction,theSEandtrendoffrequencychangeofcorrespondingfiberreinforcedconcreteareenhanced.Whenthevolumecontentofsteelfiberis3%,theSEofconcreteisabove50dBanditsfrequencyisabove1.8GHz.Moreover,intherangeof8-18GHz,steelfiber,carbonfiberandPVAfiberallcanimprovethemicrowaveabsorptionpropertiesofconcrete.Theconcretewith0.5%carbonfibercanachievethebestabsorbingproperty,theminimumreflectivityisabout-7dB;whilesteelfiberoptimalvolumefractionis2%.ThereflectivitycurveofPVAfiberreinforcedconcretefluctuateswiththefrequency,andtheminimumvalueofthereflectivityisbelow-10dB.TheresultsshowthatfiberreinforcedconcretecouldbeusedasEMI(electromagneticinterference)preventionbuildingsbyattenuatingandreflectingelectromagneticwaveenergy.

简介：ThebasestructureofinsituTiCP/Fecompositesfabricatedunderindustrialconditionwaschangedbydifferentheattreatments.Erosiveweartestswerecarriedoutandtheresultswerecomparedwiththatofwear-resistantwhitecastiron.TheresultssuggestthatthewearresistanceoftheinsituTiCp/Fecompositeishigherthanthatofwear-resistantwhitecastironunderthesanderosivewearcondition.Thewearmechanismofthewear-resistantwhitecastironwasacycleprocessthatbasesurfacewaswornandcarbideswereexposed,thencarbideswasbrokenandwearpitsappeared.WhilethewearmechanismofinsituTiCp/FecompositewasacycleprocessthatbasesurfacewaswornandTiCgrainswereexposedanddropped.ThewearresistanceofinsituTiCp/Fecompositewaslowerthanthatofwear-resistantwhitecastironundertheslurryerosivewearcondition.Undersuchcircumstance,thematerialwasnotonlyundergoneerosivewearbutalsoelectrochemistryerosionduetothecontactwithwaterinthemedium.Thewearbehaviourscanbeacombinationoftwokindsofwearandthesanderosivewearisworsethanslurryerosivewear.

简介：Carbonnanotube(CNT)reinforcedaluminummetalmatrixcompositeswereweldedbyelectronbeamweldingandthemicrostructuresofweldedjointswereinvestigated.TheresultshowedthattheinterfacialreactionhappenedbetweentheCNTsandAlmatrix,whichresultedinproducingbrittleAl_4C_3compoundsinelectronbeamwelds.Theextentofinterfacialreactionvariesgraduallyinthedepthandwidthdirection.ThelengthofthereactantsAl_4C_3becameshortduotothetemperaturegradientinthemoltenpool.ThequantityandsizeofAl_4C_3compoundsincreasedwiththeincreaseofbeamcurrentandthedecreaseofweldingspeedinthemiddlezoneofweld.However,noneedle-likephaseAl_4C_3wasobservedinHAZ.

简介：Theinfluencelawofammoniumpolyphosphate(APP)andcouplingagentsonthemechanicalpropertiesandflameretardantpropertiesofwoodpowder/PEcompositeswerestudiedbymechanicaltestandlimitedoxygenindex(LOI)test.TheexperimentalresultsshowthattheLOIofcompositesincreasedfrom18.7%to26.5%whenthecontentofAPPflameretardantwas30%,howeverthemechanicalpropertiesdecreased.ThemaleicanhydridegraftPP,titanateandsilanecouplingagentwereusedtoimprovemechanicalpropertiesofcompositesanditwasimpliedthattitanateandsilanecouplingagentcanimprovethemechanicalpropertiesofcompositesobviously.Thelimitedoxygenindexofwoodpowder/PEcompositesreached27.5%whenthecontentoftitanatewas2%.Thermogravimetricanalysis(TGA)showsthatAPPpromotedcharringandincreasedtheamountsofchar,thusprotectingtheinnermatrixandincreasedtheamountofresidualcharathighertemperature.Thetitanatecouplingagentfurtherincreasedthecharringformedandstrengthenedthethermalstability,soobviouslyincreasedtheflameretardantofcomposites.

简介：Fibrestressofglassfibrereinforcedpolymericcopmositesonloadisdeterminedbyusingopticalfibreasmodelfiberandbymeansoflaserinterferencemethod.Inaddition,theoriginationoffibrestressduringmouldingprocessofcompositesandtherelationbetweenfiberstressofloadedcompositesandexternalstressareexamined.Theexperimentsshowthatfibrestressisrelatedtomolecularstructureofinterfacialmaterialsandstructureofinterfaciallayers.Whenstressistransferredfrommatrixtofibre,eachinterfaciallayerhasdifferentstressgradientanddeformability.Thispropertycanbecharacterizedbyintroducinganinterfacialstresstransfercoefficientktothetwo-phasemodel.

简介：PP/claycompositeswithdifferentdispersions,namely,exfoliateddispersion,intercalateddispersionandagglomeratesandpanicle-likedispersion,werepreparedbydirectmeltintercalationorcompounding.TheeffectofclaydispersiononthecrystallizationandmorphologyofPPwasinvestigatedviaPLM,SAXSandDSC.Experimentalresultsshowthatexfoliatedclaylayersaremuchmoreefficientthanintercalatedclayandagglomeratesofclayinservingasnucleationagentduetothenano-scaledispersionofclay,resultinginadramaticdecreaseincrystalsize(lamellarthicknessandspherulites)andanincreaseofcrystallizationtemperatureandcrystallizationrate.Ontheotherhand,adecreaseofmeltingtemperatureandcrystallinitywasalsoobservedinPP/claycompositeswithexfoliateddispersion,duetothestronginteractionbetweenPPandclay.Comparedwithexfoliatedclaylayers,theintercalatedclaylayershavealessimportanteffectonthecrystallizationandcrystalmorphology.Noeffectisseenforsampleswithagglomeratesandpanicle-likedispersion,inregardtomeltingtemperature,crystallizationtemperature,crystalthicknessandcrystallinity.

简介：Theadvancedfabricationofin-situdendrite/metallicglassmatrix（MGM）compositesisreviewed.Herein,thesemisolidprocessingandBridgmansolidificationaretwomethods,whichcanmakethedendriteshomogeneouslydispersedwithinthemetallicglassmatrix.Uponquasi-staticcompressiveloadingatroomtemperature,almostallthein-situcompositesexhibitimprovedplasticity,duetotheeffectiveblocktothefastpropagationofshearbands.Uponquasi-statictensileloadingatroomtemperature,althoughthecompositespossesstensileductility,theinhomogeneousdeformationandassociatedsofteningdominates.Highvolume-fractioneddendritesandnetworkstructuresmakein-situcompositesdistinguishinglyplasticupondynamiccompression.In-situcompositeexhibitshightensilestrengthandsoftening（necking）inthesupercooledliquidregion,sincethepresenceofhighvolume-fractioneddendriteslowerstherheologyoftheviscousglassmatrixathightemperatures.Atcryogenictemperatures,adistinguishingly-increasedmaximumstrengthisavailable;however,aductile-to-brittletransitionseemstobepresentbyloweringthetemperature.Besides,improvedtension—tensionfatiguelimitof473MPaandfour-point-bendingfatiguelimitof567MPaaregainedforZr58.5Ti14.3Nb5.2Cu6.1Ni4.9Be11.0MGMcomposites.Highvolume-fractiondendriteswithintheglassmatrixinduceincreasedeffectivenessonthebluntingandpropagatingresistanceofthefatigue-cracktip.Thefracturetoughnessofin-situcompositesiscomparabletothoseofthetougheststeelsandcrystallineTialloys.Duringsteady-statecrack-growth,theconfinementofdamagebyin-situdendritesresultsinenhancementofthetoughness.

简介：ThefracturetoughnessandfractureworkofAl2O3/SiCprismaticceramiccompositeswasevaluatedinthispaper,whichshowedthefractureenergywasimprovedgreatly.Basedontheobservationforcrackpropagationandfracturemorphology,thefracturebehavioroftheprismaticcompositeswasanalyzed.Inthebendingtest,thecompositesdisplayedanon-catastrophicbehaviorandagracefulfailurewithreasonableload-carryingcapability.

简介：ＣａｌｃｕｌａｔｉｏｎｏｆＢｕｌｋＭｏｄｕｌｉｏｆＣａｒｂｏｎＮｉｔｒｉｄｅ／ｍｅｔａｌＮｉｔｒｉｄｅＣｏｍｐｏｓｉｔｅｓＨｏｕＱｉｎｇｒｕｎａｎｄＧａｏＪｕ（侯清润）（高炬）ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，ＴｈｅＵｎｉｖｅｒｓｉｔｙｏｆＨｏ...

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简介：这份报纸学习多相的thermoelasticcomposites的有效性质。把免费精力和吉布斯基于Helmholtz多相的composites的单个阶段，有效有弹性的张肌，热扩大的张肌，和特定的热的免费精力借助于体积一般水准被导出这些阶段免费精力。特别强调以经常紧张、经常压力的状况，修改Eshelby的micromechanics理论在被开发被放在有效的特定的热的新分析表情的推导上，在包括之间的相互作用被考虑。作为一个解说性的例子，为三阶段的thermoelastic的有效的特定的热的分析表示合成被介绍。

简介：Despitethewideusageofisotropicfibrouscompositeswithaviscoelasticpolymermatrix,noanalyticmodelfortheirmechanicalbehaviourisknown.Thispaperdevelopssuchamodelfortime-dependentYoung'smodulus,showingthatfortypicalconstituentsthetimeconstantsofcompositesareuptoabout6%greaterthanthematrixsheartimeconstant.Viscoelasticityisstronglysuppressedforstifffibresevenatmodestfibrevolumefractions.Comparisonwithknownresultsforparticleandorientedfibrecompos...

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简介：Asystematicalsimulationhasbeencarriedoutontheindentationcreeptestonparticle-reinforcedcomposites.Thedeformation,failuremechanismsandlifeareanalyzedbythreereasonablemodels.Thefollowingfivefactorshavebeenconsideredsimultaneously:creeppropertyoftheparticle,creeppropertyofthematrix,theshapeoftheparticle,thevolumefractionoftheparticleandthesize(relativesizetotheparticle)oftheindentationindenter.Forallthecases,thepowerlawrespectingtotheappliedstresscanbeusedtomodelthesteadyindentationcreepdepthrateoftheindenter,andthedetailexpressionshavebeenpresented.Thecomputersimulationprecisionisanalyzedbythetwo-phasemodelandthethree-phasemodel.Twoplacesofthestressconcentrationarefoundinthecomposites.Oneisaheadoftheindentationindenter,wherethehighstressstateisdeducedbytheedgeoftheindenterandwilldecreaserapidlyneartoasteadyvaluewiththecreeptime.Theotheroneisattheinterface,wherethehighstressstateisdeducedbythemisfitofmaterialpropertiesbetweentheparticlesandmatrix.Ithasbeenfoundthatthecreepdissipationenergydensityotherthanastressparametercanbeusedtobethecriteriontomodelthedebondingoftheinterfaces.Withthecriterionofthecriticalcreepdissipationenergydensity,apowerlawtotheappliedstresswithnegativeexponentcanbeusedtomodelthefailurelifededucedbythedebondingofinterfaces.Theinfluencesoftheshapeoftheparticlesandthematchingofcreeppropertiesofparticleandmatrixcanbediscussedforthefailure.Withacrackmodel,thefurthergrowthofinterfacecrackisanalyzed,andsomeimportantexperimentalphenomenacanbepredicted.Thefailuremechanismwhichtheparticlewillbepunchedintomatrixhasbeenalsodiscussed.Thecriticaldiflerencesbetweenthecreeppropertiesoftheparticlesandmatrixhavebeencalculated,afteraparameterhasbeendefined.Intheviewofcompetitionoffailure

简介：AnewtypeofSiO_2-MgO-CaO(SMC)whiskerwasusedtomodifyhighdensitypolyethylene(HDPE).Themeltingbehaviorandcrystallinitywereinvestigatedbydifferentialscanningcalorimetry(DSC).ThedispersionofwhiskersandinterfacialadhesioninthepreparedHDPE/SMCwhiskercompositeswereinvestigatedbyscanningelectronmicroscopy(SEM).Themechanicalpropertieswereevaluatedbymechanicaltestsanddynamicmechanicalanalysis(DMA).DSCdataindicatedthatthemeltingtemperatureandthecrystall...

简介：Themixedmatrixmembranes(MMMs)weredevelopedbyincorporatinggraphiteoxide(GO)flakesfunctionalizedwithironoxide(Fe3O4)intoPebaxmatrix.ThePebax/Fe3O4-GOMMMswereusedtoseparateCO2/CH4andCO2/N2gasmixture.TheresultsshowedthattheMMMswithmagneticalignmentpresentedthebettergasseparationperformancethanthatofrandomarrangementofPebax/Fe3O4-GOmixedmatrixmembranes.ThereasonwasthattheFe3O4-GOflakesarrangedmagneticallyinthemembraneplayedamultipleroleinimprovingtheperformanceofMMMs.Firstly,undertheactionofthemagneticfield,themagneticalignmentofFe3O4-GOflakesinPebaxmatrixconstructedtheshortertransferpathforgasmolecule,increasingtheCO2permeability.Secondly,thehydroxylgroupsinGOflakesandthepresenceofFe3O4havestrongerbindingforceforwater,improvingtheCO2solubilityselectivity.Thirdly,thebetterinteractionbetweenthemagneticalignmentofGOcompositesandpolymermatrix,reducedtheinterfacedefects.Especially,theoptimumgasseparationperformsneewasobtainedattheFe3O4-GOflakescontentof3wt%inPebaxmatrixatverticalarrangementwithselectiv让yof47and75forCO2/CH4andCO2/N2,respectively,andCO2permeabilityof538Barrerat0.2MPaandroomtemperature.

简介：Theapplicabilityandlimitationofseveralquadraticstrengththeorieswereinvestigatedwithrespectto2D-C/SiCand2.5D-C/SiCcomposites.Akindofdamage-basedfailurecriterion,referredtoasD-criterion,isproposedfornonlinearceramiccomposites.Meanwhile,thenewlydevelopedcriterionispreliminarilyvalidatedundertension-shearcombinedloadings.ThepredictionshowsthatthefailureenvelopegivenbyD-criterionislowerthanthatfromTsai–HillandHoffmancriteria.Thisrevealsthatthedamage-basedcriterionisreasonableforevaluationofdamage-dominatedfailurestrength.

简介：Chitosan/cellulosenanocrystals(CS/CNCs)composites与计算机数值控制的不同内容被准备。由于计算机数值控制和计算机数值控制的同类的分散，CS的透明性很好被保留，CS的全面机械性质显著地被改进。而且，因为CS和计算机数值控制是biocompatible材料，获得的composites潜在地是noncytotoxic和罐头的房间增长测试表演满足生物医学的应用的安全要求。这些优点在商业塑料的地里铺平CS的潜在的应用的道路并且鼓励CS同样环境友好的材料和生物医学的材料的使用。