简介:Therulessuchasprocessparametersaffectingjointpropertiesandtheevolutionprincipleofweld'smicrostructurehavebeenresearchedbyadoptingdiffusionweldingprocesstoconnectSiCw/6061Alcomposite.ExperimentalresultsshowthatthereexistsacriticaltemperatureregionbetweensolidandliquidphaselineofSiCw/6061Alcomposite,andtheregionwillshrinkwiththeincreasingofweldingpressure.Whendiffusionweldingoccurredunderthecriticaltemperatureregion,weldingjointexhibitsbadpropertyofbonding,andthematrixandthereinforcementcan'tbondeffectively.Whendiffusionweldingoccurredinthecriticaltemperatureregion,thestrengthofweldingjointchangeswidelywiththevariationofweldingtemperature.Whenweldingtemperaturevariesin10℃,thestrengthofweldingjointwillchangeobviously.Onlywhenweldingtemperatureishigherthanthecriticaltemperatureregion,stablejointpropertiescanbeobtained.Simultaneouslythematrixandthereinforcementhasbetterinterfacialbondedindiffusionweldinginterface,andnoobviousinterfacereactionoccurred,andthusdiffusionweldingofSiCw/6061Alcompositecanbesuccessfullyrealized.
简介:TheweldabilityofSiCw/6061Alwasinvestigated.Fromtheresultsofexperiments,itisfoundthatthestrengthofjointismainlyinfluencedbyweldingtemperature,andhighstrengthofjointisobtainedunderweldingtemperaturebetweenliquidusandsolidusofmatrixalloy.DiffusionweldingofSiCw/6061.Alwassuccessfullyrealizedwithappropriateweldingparameters.
简介:Coppercoatingwasdepositedonthesurfaceofaluminumboratewhiskerbyanelectrolessplatingmethod.Thismethodwasusedtomodifytheinterfacialpropertyofsqueeze-castingaluminumboratewhiskerreinforced6061Almatrixcomposite.Interfaceobservationindicatesthatthespinelreaction(MgAl2O4)ishinderedbythecoppercoating,andthedifferenceininterfacialreactiondegreeaffectsthetensilepropertyandagingbehaviorofthecomposite.Forthecompositewithlessspinelreaction(MgAl2O4),itspeak-agingprocessarepostponedduetolessdepletionofmagnesium.Onthefracturesurfaceofcopper-coatedcompositedimplesandfracturesofwhiskersaremore,butonthefracturesurfaceofuncoatedcompositepull-outofwhiskersaremorethanthatonthecoatedone.Inuncoatedcompositethefracturegenerallyoriginatesfromthenear-interface-region.
简介:TheinteractionbetweenZn-AleutecticalloyandAl2O3p/6061Alcompositesinthevacuumfurnacewasinvestigated.Greatattentionhasbeenpaidtotheelementsdiffusion,themicrostructureandformationoftheinterfacebetweenZn-AIeutecticalloyandAl2O3p/6061Alcomposites.ExperimentalresultsshowthatZn-AleutecticalloyhasagoodwettingabilitytoAl2O3p/6061Alcompositesandthewettingangledecreaseswithincreasingthetemperatureinvacuum.Aftertheinteraction,aninteractionlayerformsbetweenZn-AIalloyandAl2O3p/6061Alcomposites.Thephasesintheinteractionlayermainlyconsistofα-Al(Zn),Al2O3andCuZn5resultedfromthediffusionofelementsfromtheZn-Alalloy.SeveralporositiesdistributeintheregionneartheinterfaceoftheZn-Alalloy/interactionlayer.TheamountofshrinkagevoidsintheinteractinglayerisrelevanttothepenetrationofZnelementintoAl2O3p/6061Alcompositeswhichisafunctionoftemperature.SoitisnecessarytolowerheatingtemperatureinordertolimittheZnpenetration.
简介:选择不同粒径的6061A1粉末和SiC颗粒,采用真空热压法制备含35%SIC体积分数的SiCo/6061AI复合材料,研究不同级配比对复合材料显微组织和抗拉强度的影响。结果表明:复合粉末的粒径级配比可影响复合材料的微观组织和力学性能;当增强体颗粒粒径为15μm时,随基体6061粉末与SiC颗粒粒径比降低,SiC颗粒在复合材料中的分布越来越均匀,抗拉强度提高:当基体6061A1粒径为10Bin时,随SiC颗粒粒径减小,复合材料微观组织的均匀性降低,但抗拉强度提高。并建立了理想的复合粉末颗粒分布模型,模型的理论计算结果与Slipenyuk公式计算结果接近。
简介:采用湿磨-高能球磨法对高粒径比的6061Al粉末和SiC混合粉末进行预处理,利用真空热压烧结法制备SiCp/6061Al复合材料。用XRD、SEM、TEM、拉伸强度等测试方法研究球磨时间对复合粉末形貌及复合材料组织和性能的影响。结果表明:在球磨过程中铝粉和SiC颗粒形成复合聚合体,采用乙醇做控制剂,可有效地抑制冷焊反应发生;随球磨时间延长,复合聚合体逐渐变薄并最终断裂;聚合体中碳化硅的含量先增高后降低;铝粉中晶粒尺寸逐渐降低,位错增多;SiC颗粒发生碎化,在基体中分布更加均匀;复合材料的拉伸强度提高,可达到258MPa。
简介:Thejoiningofa6-mmthicknessAl6061toStainlesssteel304hasbeenperformedbysolidstatewelding.Aselectionmethodofoptimumfrictionweldingconditionusingneuralnetworksisproposed.Thedatausedforanalysesarethefrictionstirweldingcondition,theinputparametersofthemodelconsistofweldingspeedandtoolrotationspeed.TheoutputsoftheANN(ArtificialNeuralNetwork)modelincludesresultingparameters,namely,maximumreachedtemperature,andheatingrateforbothaluminumalloy6061andstainlesssteel304duringfrictionstirweldingprocess.Theresultsofanalysissuggestthattheproposedmethodisaneffectiveonetoselectanoptimumweldingcondition.GoodperformanceoftheANNmodelwasachieved.Thecombinedinfluenceofweldingspeedandtoolrotationspeedonthemaximumreachedtemperatureandheatingrateforbothaluminumalloy6061andstainlesssteel304frictionstirweldingwassimulated.AcomparisonwasmadebetweentheoutputoftheANNprogramandfiniteelementmodel.Thecalculatedresultswereingoodagreementwiththatoffiniteelementmodel.
简介:扔的near-liquidus准备的6061件半固体铝合金化工物品借助于Gleeble-3500热机械的模拟器处于半固体状态被压缩。在在不同温度和紧张率的真压力和真紧张之间的关系与70%的变丑度被学习。微观结构在变丑过程期间被描绘。半固体合金的变丑机制和形成thixo性质被分析。结果证明同类并且6061Al合金由扔技术的near-liquidus生产了的半固体的非树突微观结构能与对与通过再热的最容易溶解的作文在球形附近的谷物和液体阶段镇静的形成thixo合适的微观结构被转变成半固体状态过程。变丑温度和紧张率显著地影响山峰压力而非稳定流动应力。到处于半固体状态的变丑的抵抗随变丑温度的增加和紧张率的减少减少。在稳定的thixotropic变丑舞台,thixotropic性质是一致的,并且主要变丑机制是在稳固的粒子和稳固的粒子的塑料变丑之间旋转或滑动。
简介:本文主要研究了晶须体积分数对短纤维增强金属基SiCw/Al复合材料析出与时效的影响。研究表明晶须体积分数对SiCw/Al复合材料的析出与时效的影响较大。随着晶须体积分数的增大,SiCw/Al复合材料的时效析出相明显增多,硬度值显著增大。
简介:Therelationshipbetweentheplane-orientationfunctionandthespace-orientationfunctionofwhiskersinwhisker-reinforcedmetalmatrixcompositeswasanalyzedtheoretically.Theactualorientationofwhiskersintheas-cast20%SiCw/Mgcomposite(SiCwcontentinvolumefraction)wereinvestigated,andtheelasticmodulusofthecompositewasmeasuredwithanultrasonicvelocityanalyzer.Resultsshowthatthereisanevidentdifferencebe-tweentheplane-orientationfunctionandthespace-orientationfunctionofwhiskersandthespace-orientationfunctioncanrepresenttheactualconditionofthecomposite.Onlybyusingthespace-orientationfunctionofwhiskers,thedifferenceofelasticmodulusoftheas-castcompositeindifferentdirectionscanbeexplainedreasonably.
简介:近日,2006年索尼数码单反相机新品发布会在京举行.索尼在会上发布了备受期待的首款数码单反相机α100.同时发布的还有21支可更换镜头以及包括闪光灯等在内的40余款配件。此间.卡尔·蔡司也宣布为索尼数码单反提供镜头.这批镜头将以ZA命名.以表明是卡尔·蔡司为索尼α专门研发的。索尼收购柯美的单反相机部门后不长的时间就推出了首款数码单反相机,表明了其进入数码单反领域的坚定决心。