简介:Themicrostructuresaftercastingandextruding,themechanicalpropertiesandelectricalconductivityafterRRAtreatmentofconventionalDCcastingandlowfrequencyelectromagneticcasting(LFEC)7075aluminumalloywereinvestigated.TheresultsshowedthatfinergrainswhichdistributedmorehomogeneouslywasobtainedinLFECingotscomparedwiththoseconventionalDCingots.TheextrudedbarsofLFECalloykeptitsfinegrainfeaturesoforiginalas-caststructure.IntheRRAtreatment,withtheextensionofsecondagingtime,thetensilestrengthandhardnessofalloydecreased,buttheelectricalconductivityincreased.Meanwhile,asthesecondagingtemperatureraised,thephasechangerateinprecipitationalsoincreased.Underthesameconditions,extrudedbarsofLFECalloyhadbetterperformancethanthatofconventionalDCcastalloy.TheoptimumRRAheattreatmentprocesswas120℃/24h+180℃/30min+120℃/24h.TheLFECextrudedbarsacquiredtensilestrength676.64MPa,hardness198.18,andelectricalconductivity35.7%IACSrespectively,whichwerehigherthanthatintheT6temper,indicatingthatanotableRRAresponsetakesplaceinLFECextrudedbars,whosesecond-stepretrogressiontimewas30min,anditwassuitableformassproduction.
简介:我们集中于与Ni-Al金属间化合的混合物扔合金由的ligth重量的表面加强在原处改进非铁的扔的表面性质的燃烧反应部件。在我们的以前的工作,元素的Ni和艾尔粉末紧缩的绿色被SHS(自我繁殖的高温度合成)反应到形式Ni3Al金属间化合的化合物有熔融的艾尔合金并且同时的热的反应与艾尔扔结合了合金。但是象微小的裂缝和孔那样的一些缺点在反应协议被仍然是。我们因此使用了压力阻止热裂缝并且与液体艾尔合金充满毛孔由压榨扔过程。压缩艾尔合金与Ni3Al金属间化合的混合物结合了是sectioned并且由光显微镜学和扫描电子显微镜学(SEM)观察了。在结合的接口附近并且在反应协议形成的intermetallics的stoichiometric作文被散光谱学(版本)和电子探查的精力识别微分析(EPMA).Si富人层被艾尔的顺序的团结在结合的接口附近在艾尔合金方面上形成合金。在反应Ni3Al协议观察的孔与液体艾尔合金被充满。从熔融的艾尔合金的Si粒子在反应Ni3Al金属间化合的协议的毛孔被检测。扔合金和Ni3Al金属间化合的化合物的艾尔被把压力用于液体艾尔合金很很熟加入。
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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:TechnologicalprocessofrareearthsealinganodizedLY12(2024)alloyisintroduced.Corrosionbehaviorofthefilmwasstudiedbypolarizationcurvesandelectrochemicalimpedancespectroscopy(EIS).Theresultsshowedthatthecoatingremainedpassivityatthepotentialrangefromtheopencircuitpotential(-780mV)to-250mVinNaClsolution.Whenthepotentialexceeded-200mV,corrosionreactionhappenedonthecoating.theresultsofElSanalysiswasconsistentwiththeresultsofpolarizationcurves.
简介:Al-4。5Cu-5Pb合金被扔的沙和寒冷准备。一样的合金也是在1.6MPa的一个煤气的压力扔的水花。微结构特征展览一对为沙和寒冷铸石金的好树枝状的形态学粗糙。Equiaxed谷物被观察因为水花形成了合金。穿测试采用一根大头针--在圆盘上类型安装,揭示更加更低与寒冷和沙铸石金的相比水花穿扔的合金。词法特征在显示的标本和碎片上穿轨道混合oxidative-cum-adhesive为在现在的调查测试的这些合金穿机制。(编辑作者摘要)36个裁判员。
简介:磨擦促使处理(FSP),FSW的一个变化(磨擦促使焊接)能局部地消除的一种新兴的表面工程技术正在扔缺点和精制微观结构,从而改进material.FSP的机械性质能也通过厚度生产有细密纹理的微观结构给予技术包含跳入很快旋转的superplasticity.The,非可消费的工具,包括一根介绍大头针和更大的直径肩膀,进表面然后越过表面穿越工具。大头针和肩膀磨擦加热在从而改进机械性质的处理区域改变谷物结构的表面。这篇论文在微观结构和渗出的演员组的机械性质上论述FSP的效果2285铝合金在三不同喂率viz.10,12和15mm/min.Withfeed速度的增加材料被观察增加了也增加的impactstrength.FSP张力并且有坚硬和韧性价值的增加的收益力量另外。观察详细被列出了并且图片地代表了。
简介:疲劳行为在期间高测试的周期疲劳和5A06铝的张力的行为就anisotropy而言的合金被学习。标本的二种类型包括的纵的标本(与滚动平行方向)并且横向的标本(对滚动方向垂直)被准备。红外线的thermography被采用到监视温度进化在疲劳和张力的测试期间。在二个方向的温度进化曲线对比地被分析。它被发现温度进化在疲劳过程期间拥有四阶段:起始的温度上升舞台,慢温度衰落阶段,快速的温度上升阶段,和物件顶端的装饰物温度衰落舞台。产生四个阶段的机制的热被讨论。明显的差别罐头在疲劳力量在纵的标本和横向的标本之间被发现并且使生活疲劳。纵的标本的疲劳力量和疲劳生活比横向的标本的那些高。在期间张力并且疲劳测试过程,在横向的方向的破裂温度在纵的方向比那高。借助于红外线的thermography的疲劳力量预言由传统的方法与那有好一致性。
简介:Theeffectsofconcurrentpulsesinholdingdurationonsuperplasticityof2091Al-Lialloyhavebeeninvestigatedinthispaper.Theresultsofsuperplasticdeformationshowedthatconcurrentpulsesinholdingdurationdecreasedtheoptimumholdingtimeforsuperplasticdeformation(ε=3.33×10-2s,T=500℃)from15to5minandincreasedelongation(δ)from530to550%.Themetallographicobservationsshowedthatthespecimensappliedlybyconcurrentpulsewerecom-pletelyrecrystallizedafterholding5minat500℃,andgrainsrefinedtoabout2μm,andthosespec-imensunappliedcurrentpulseswerepartlyrecrystallizedevenafterholding15minat500℃.theelectronprobeanalysesindicatedthatconcurrentpulsespromotedatomicdiffusion.Itispointedoutthatconcurrentpulsesaccelerateatomdiffusionanddislocationmotion.increasenucleationrateofrecrystallizationanddecreasetheoptimumholdingtimeforsuperplasticdeformationandincreasesuperplasticproperties.
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简介:Nanocrystallinesurfacelayersandgradientnanostructurein5182aluminumalloyhavebeenproducedthroughsurfacemechanicalattritiontreatment(SMAT).Theresultsindicatethatthegradientnanostructurecannotonlyimprovethemechanicalpropertiesof5182Alalloy,butalsohasacertaineffectonthePortevin-LeChatelier(PLC)effect.Theyieldandultimatetensilestrengthof5182AlalloywithSMATaresignificantlyimprovedcombiningwiththedecreaseoffractureelongationcomparedwiththeas-receivedone.ThePLCeffectof5182AlalloycouldbeeffectivelypostponedbytheformationofgradientnanostructureafterSMAT,ItleadstotheincreaseofcriticalstrainofthePLCeffect,moreconcentrateddistributionofserratedstrain,andincreaseofaveragestressamplitudeinspecialstrainrange.TheinfluenceofgrainsizeandgradientnanostructureonthePLCeffectof5182Alalloywasalsodiscussedindetail,Grainrefinementcouldsharplyincreasethedensityofdislocationsandhinderthemovementofdislocations,whichresultsinthedecreaseofmovingspeedofdislocationsandthemoreconcentrateddistributionofsoluteatoms.Thesoluteatomswouldaggregatetoformnanoprecipitatesandfurtherimpedemovementofdislocation.ThestrongerinteractionbetweenthedislocationsandthenanoprecipitatesisthemainmechanismofpostponedPLCeffect.
简介:AdditionofAl-5Ti-1Balloytomoltenaluminumalloyscanrefineα-Algrainseffectivelyandtherebyimprovetheirstrengthandtoughness.TiAl3andTiB2inAl-5Ti-1Balloyarethemainsecondary-phaseparticlesforrefinement,whiletheunderstandingontheeffectoftheirsizesonα-Algrainrefinementcontinuestobefragmented.Therefore,Al-5Ti-1Balloyswithvarioussizesandmorphologiesofthesecondary-phaseparticleswerepreparedbyequalchannelangularpressing(ECAP).Evolutionofthesecondary-phaseparticlesduringECAPprocessandtheirimpactonα-AlgrainrefinementwerestudiedbyX-raydiffractionandscanningelectronmicroscope(SEM).ResultsshowthatduringtheECAPprocess,micro-cracksfirstlyappearedinsideTiAl3particlesandthengraduallyexpanded,whichresultedincontinuousrefinementofTiAl3particles.Inaddition,micro-distributionuniformityofTiB2particleswasimprovedduetotheimpingementofTiAl3particlestoTiB2clustersduringdeformation.ExcessivelylargesizesofTiAl3particleswouldreducethenumberofeffectiveheterogeneousnucleusandthusresultedinpoorgrainrefinementeffectiveness.Moreover,excessivelysmallTiAl3particleswouldreduceinhibitoryfactorsforgraingrowthQandweakengrainrefinementeffectiveness.Therefore,anoptimalsizerangeof18-22μmforTiAl3particleswassuggested.
简介:AhypereutecticAl-Sialloypowderwaspreparedbyultrasonicgasatomizationprocess.Themorphologies,microstructureandphaseconstituentofthealloypowderwerestudied.TheresultsshowedthatpowderofthealloywasveryfineanditsrnicrostructurewasmainlyconsistedofSicrystalsplusintermetalliccompoundAl9FeSi3,whichwere.veryfineanduniformlydistributed.
简介:被动导致电影的压力和危险性在在各种各样的pH价值的3.5%钠氯化物答案的7050铝合金的SCC被慢紧张率测试调查(SSRT)并且流动应力微分方法。结果证明到SCC的被动导致电影的压力和危险性与增加pH减少了价值什么时候pH7,当他们与增加pH增加了时价值什么时候pH>7。然而,当,腐蚀类型被解释脱落腐蚀什么时候pH=1并且14,并且没有电影,在标本的表面上形成。整个变化与pH导致电影的应力和SCC危险性阴谋当,价值两个都被介绍山谷形状。导致电影的压力的标志和数量与被动电影的作文有关,它用X光检查光电子被分析光谱学(XPS)。
简介:在磨擦促使焊接(FSW),工具几何学在联合质量起一个重要作用。为了改进磨擦的机械性质,促使焊接的臀部(FSLW)关节,有一根颠倒线程的大头针的一个工具在现在的学习被设计。用是的2024-T4铝合金,研究目标,有完整线程的大头针的工具和颠倒线程的大头针在FSLW被使用。结果用一样的参数联合看了那是否,用颠倒线程的大头针联合的FSLW拥有了更大的有效的表厚度(EST),更大的臀部宽度和更好的臀部砍失败力量。与完整线程的大头针相比,FSLW关节的破裂模式变化了从砍当颠倒线程的大头针被使用时,折断模式到张力的破裂模式。破裂形态学介绍了可锻的骨折。
简介:从同样渗出的镁合金Mg-3%Al-1%Zn(AZ31)营舍准备的样品在低周期的疲劳测试被利用以便调查频率依赖者疲劳生活。充分颠倒的控制紧张的紧张压缩疲劳测试在空中在1Hz和10Hz的频率被执行。微观结构被光显微镜学(OM)和扫描电子显微镜学(SEM)检验。当紧张振幅比0.2%低时,疲劳生活与装载频率展出了积极关联,并且twinning的活动在10Hz被增加。当紧张振幅比0.2%高时,重要twinning在生活被发现独立于频率的这二频率,和疲劳被观察。为这频率相关的疲劳一生的可能的原因可能由于在装载频率和紧张振幅之上的twinning的依赖。
简介:Theliquidphasebehaviorofthefine-grained5083Alalloyobtainedthroughthermomechanicalprocesswasinvestigatedduringthetensiletestsinatemperaturerangeof380-570-Candstrainraterangeof4.17×10-4-1.0×10-2s-1.Themaximumelongation530%ofthefine-grained5083Alalloywasobtainedat550-Cand4.17×10-4s-1.Fractureanalysisbyscanningelectronmicroscopy(SEM)indicatedthattheformationoffilament(formedbyliquidphase)wasgreatlyaffectedbythetensiletemperatureandstrainrate.Theresultsalsoshowedthattheoptimummorphologyofformedfilamentwasobtainedat550-Candastrainrateof4.17×10-4s-1.Theeffectofliquidphaseonsuperplasticdeformationofthealloywasfurtherdiscussed.
简介:这研究的多数专注于开发自立磨擦促使焊接(SSFSW)由大凹面组成的工具上面的肩膀和一个小凸的更低的肩膀,和为在铝做可靠焊接的过程凹陷挤出。5-mm-thick6082-T6铝合金是自立磨擦搅动以800r/min的经常的工具旋转速度焊接了。在微观结构和机械性质上焊接速度的效果被调查。横向的张力的测试的结果显示关节的张力的力量增加了,延伸与增加焊接速度减少了。SSFSW关节的microhardness的整个价值与增加从10焊接速度到200mm/min增加了。没有缺点的关节以更低的焊接速度被获得,张力的破裂在影响热的地区(HAZ)被定位邻近进展方面上的thermo机械地影响的地区(TMAZ)。在SSFSW工具附近的弄软的金属的流动模式的调查表明弄软的金属的流动模式被二个肩膀和stir大头针驾驶。在紧张的标本的失败介绍了可锻的破裂模式。