学科分类
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42 个结果
  • 简介:伍德composites能通常在三部分被分类:把压成薄片的composites,混合composites和渗透的composites。每部分有它的自己的特征和罐头进一步被划分。这篇论文在中国介绍历史和木头composites的开发的国家。关于把胶水压成薄片的木材的研究是稀罕的,工业几乎不来到是。成就的一个伟人在混合composites被获得了,它是很好工业化的。scrimber上的许多研究被做了,中国研究人员正在寻找在中国开发scrimber工业的一个可行方法。中国研究人员也在学习木头塑料composites(世界和平理事会)花了那么多精力,但是它一直不由于高费用是工业化的。

  • 标签: WOOD COMPOSITES RESEARCH ADVANCE China
  • 简介:Collagenisthemajoracellcarofconnectivetissueproteininanimals,accountingforabout25%ofthetotalbodyproteinofvertebrates.Anessentialfeatureofthistypeofbiomaterialisthatitdegradesinbiologicenvironments,eventuallydisap-pears,andleavesnopermanentforeignresidue.Averypracticalaspectoftheuseofcollagenisitseaseofpreparationanditswidespreadoccurrenceinnature.Thus,col-lagenhasbeenemployedasabiomaterialinalmosteveryphysicalform.Forexam-ple,collagenfibrescanbeusedasasubstratefornerveregeneration,tendonligament

  • 标签: biomaterial TENDON BIOLOGIC COLLAGEN LIGAMENT COLLAGEN
  • 简介:FractureCharacteristicsofSiC(p)/AlCompositesGuHongwei;CaoLi;YuanGuansen;LiuAnsheng;WuZiqinandChenLanfeng(古宏伟),(曹利),(袁冠森),(刘安生...

  • 标签: SIC AL COMPOSITE
  • 简介:Inthispapertheresultsofahigh-speedtensionexperimentoftheSiC_w/Alcompositehavebeenreportedandasimplifiedtheoreticalmodelhasbeendevelopedtostudythefracturemechanismofcompositesinhigh-speedtension.Thistheoreticalmodelprovidesanewexplanationfortheincreaseofdynamicfracturestrengthofcompositesinhigh-speedtension.

  • 标签: COMPOSITE material HIGH-SPEED tension FRACTURE MECHANICS
  • 简介:Thedynamicmechanicalpropertiesofwoodpowder/polypropylenecompositeswithdifferentwoodcontenttreatedanduntreatedwiththecompatibilizerhavebeenstudied.Ithasbeenfoundthatadditionofwoodpowdersandthecompatibilizercanbothimprovetheviscoelasticityofcomposites.Glasstransitiontemperature(Tg)ofappropriatewoodpowder-filledcompositesdecreased.Thevalueforthestoragemodulus(G')increasedgraduallywithincreasingwoodpowdercontent.Theadditionofthecompatibiliz...

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  • 简介:ThefracturebehaviorofSiCp/A356compositeatroomandhightemperatureswasstudied.Undertensilestressconditionatroomtemperature,thefractureismostlyacombinationofthebrittlefractureofSiCparticlesandductilefractureofA356matrix.Asthetensiletemperatureincreases,thecompositechangesthemainfracturebehaviortotheseparationfractureofthebondingsurfacebetweenSiCparticlesandA356matrix.Whenthetensiletemperaturereaches573K,thefracturebehaviorofthecompositesisalmostthewholeseparationfractureofthebondingsurface,whichisthemainstrengtheningmechanismathightemperature.Underthecyclestressconditionatroomandhightemperatures,themainfracturebehaviorofthecompositesisalwaysacombinationofthebrittlefractureofSiCparticlesandductilefractureofA356matrix.However,underthecyclestressathightemperature,cyclebehaviorofthecompositeschangesfromcyclehardeningatroomtemperaturetothecyclesofteningathightemperature.

  • 标签: SiCp/A356 COMPOSITES BRITTLE FRACTURE DUCTILE FRACTURE
  • 简介:Agroupofpoly(phthalazinoneethersulfoneketone)/potassium-titanate-whisker(PPSEK/whisker)compositeswaspreparedbycoprecipitationfromsolution.Thewhiskersurfacewasmodifiedusingtitanatecouplingagentpriortoblending.Thetensile,impact,morphologyandthermalpropertiesofthemouldedcompositeswereinvestigated.Themeasurementsshowedthatthetensilestrengthandimpactstrengthofthecompositesincreasedwithincreasingwhiskerscontentupto10to20phr,thereaftertheyshowedadecreaseinthewhiskerscontentreached40phr.Atthesametime,themodulusofthecompositesincreasedwithincreasingwhiskerscontent.Scanningelectronmicroscopystudiesrevealedthatthewhiskerswithinthecompositesweredisperseduniformlybytreatedwithcouplingagent.Finally,thermogravimetricanalysisshowedthattheheatresistanceofthecompositestendedtoincreasewithincreasingwhiskercontent.Theresultswereanalysedanddiscussedintermsofestablishedmodelsofthebehaviourofshort-fiberreinforcedcomposites.

  • 标签: 钛酸钾晶须 PPESK化合物 酞菁乙醚砜酮 抗热性 工程聚合体 热塑性塑料
  • 简介:Inordertoimprovethemechanicalpropertiesofpolypyrrole,compositesweremadebyelectropolymerizingpolypyrroleinapolyurethanematrix.Polypyrrole/polyurethane(PPY/PU)compositefilmscontainingCLO4-,BF4-orCH3-C6H4-SO3-counterionsweremadeinavarietyofsolventsystemsandcharacterizedbySEM,electronicconductivity,FTIR,andmechanicalproperties.Compositefilmsshowingmuchgreaterfiexibilitythanpurepolypyrrolewereobtained,buttheirelectronicconductivitiesweresubstantiallylower.Measuredeonductivitiesrangedfrom0.001to8S/cm,tensilestrengthsfrom44to592psi,andelongationtofailurefrom3to70%.

  • 标签: POLYURETHANE ELONGATION tensile showing polymerization substantially
  • 简介:在结构的常规基于可靠性的最佳设计,可靠性基于概率假设被计算,并且设计目的和限制被看作确定的。在许多情况中,然而,在那里存在在设计目的和限制功能的一些模糊因素。在这篇论文,模糊可靠性和模糊限制被介绍为把压成薄片的composites建立模糊基于可靠性的最佳模型。方法在这篇论文开发了的例子表演能把考虑给可靠性需求和结构的经济方面。因为模糊reliability-basedoptimum设计是一个“软”的图案,现在的结果为结构的可靠性的有效评估提供新方法论并且带给我们一个其他的最佳设计想法。

  • 标签: 模糊可靠性 模糊约束性 最佳安全水平 模糊综合评估
  • 简介:ThebasestructureofinsituTiCP/Fecompositesfabricatedunderindustrialconditionwaschangedbydifferentheattreatments.Erosiveweartestswerecarriedoutandtheresultswerecomparedwiththatofwear-resistantwhitecastiron.TheresultssuggestthatthewearresistanceoftheinsituTiCp/Fecompositeishigherthanthatofwear-resistantwhitecastironunderthesanderosivewearcondition.Thewearmechanismofthewear-resistantwhitecastironwasacycleprocessthatbasesurfacewaswornandcarbideswereexposed,thencarbideswasbrokenandwearpitsappeared.WhilethewearmechanismofinsituTiCp/FecompositewasacycleprocessthatbasesurfacewaswornandTiCgrainswereexposedanddropped.ThewearresistanceofinsituTiCp/Fecompositewaslowerthanthatofwear-resistantwhitecastironundertheslurryerosivewearcondition.Undersuchcircumstance,thematerialwasnotonlyundergoneerosivewearbutalsoelectrochemistryerosionduetothecontactwithwaterinthemedium.Thewearbehaviourscanbeacombinationoftwokindsofwearandthesanderosivewearisworsethanslurryerosivewear.

  • 标签: 钛铁合金 腐蚀性表面 磨损装置 热处理
  • 简介:Fibrestressofglassfibrereinforcedpolymericcopmositesonloadisdeterminedbyusingopticalfibreasmodelfiberandbymeansoflaserinterferencemethod.Inaddition,theoriginationoffibrestressduringmouldingprocessofcompositesandtherelationbetweenfiberstressofloadedcompositesandexternalstressareexamined.Theexperimentsshowthatfibrestressisrelatedtomolecularstructureofinterfacialmaterialsandstructureofinterfaciallayers.Whenstressistransferredfrommatrixtofibre,eachinterfaciallayerhasdifferentstressgradientanddeformability.Thispropertycanbecharacterizedbyintroducinganinterfacialstresstransfercoefficientktothetwo-phasemodel.

  • 标签: interface COMPOSITES stress transfer optical FIBRE
  • 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.

  • 标签: 聚丙烯 粘土 散射 结晶化 形态学
  • 简介:ThefracturetoughnessandfractureworkofAl2O3/SiCprismaticceramiccompositeswasevaluatedinthispaper,whichshowedthefractureenergywasimprovedgreatly.Basedontheobservationforcrackpropagationandfracturemorphology,thefracturebehavioroftheprismaticcompositeswasanalyzed.Inthebendingtest,thecompositesdisplayedanon-catastrophicbehaviorandagracefulfailurewithreasonableload-carryingcapability.

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

  • 标签: BULK MODULUS Carbon NITRIDE METAL NITRIDE
  • 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

  • 标签: 刻痕 蠕变试验 计算机模拟 颗粒增强复合材料 机械性能
  • 简介:Theeffectofwoodspecies(ChinesefirandPoplar),woodfibercontent(10%,25%,40%)andwoodfibersizes(16to32mesh,32-65mesh,above65mesh)onthepropertiesofthewoodfiber-Polypropylenecompositeswerestudiedinthispaper.Theresultsindicatethattheeffectofwoodfibercontentandsizeincompositeweremoreimportantthanthatofchosenwoodspecies.Comparedwithpolypropylenewithoutwoodfiber,theflexuralstrengthofthecompositesincreasedwhenaddingwoodfiberintopolypr...

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