简介:微结构和电子横梁的机械描述焊接了伪造Ti-6Al-4V的关节被调查。Microhardness测试显示熔化地区(FZ)的坚硬比影响热的地区(HAZ)和贱金属的高。张力的结果证明焊接关节的机械性质以静态的力量与贱金属的那些是可比较的并且根据在微观结构和焊接关节的机械性质之间的关系。焊接的最终的张力的强度等于时漏关节的,它显示横向的FZ的纵的FZ和那些的机械性质是一样。基础材料,关节,和焊接标本的Macromechanical行为和macrofracture和microfracture被观察。在标本破裂现象的三种类型之中的比较揭示下列特殊差别:(1)破裂模式,(2)在中央区域的酒窝模式的显微图,并且(3)在中央区域和转变区域的酒窝的尺寸。
简介:微观结构和形成的激光固体(LSF)的机械性质上的热处理的效果Ti-6Al-4V合金被调查。温度的影响和答案处理和老化处理的时间被分析。结果证明LSFed样品的微观结构与300μm的平均谷物宽度由Widmanstättenα板条和在圆柱的优先的β谷物针状的一些组成,它沿着免职方向(Z)从底层取向附生地成长。解决方案处理在处理主要影响的主要、第二等的α板条,和老化的宽度,方面比率,和卷部分上有重要效果主要α板条和宽度的方面比率和卷部分和第二等的α板条的卷部分。当样品是与答案处理对待的热时,球状的α阶段首先在LSFed样品被观察(950°C,冷却的8h/air(交流))或与答案处理(950°C,1h/AC)并且老化处理(550°C,在8h/AC上面)分别地。在热处理期间在LSFedTi-6Al-4V合金变粗和α阶段的globularization机制被介绍。为LSFedTi-6Al-4V合金获得好综合机械性质,优化的热处理政体被建议。
简介:pH价值和Y2Y23-SiO2(Y-Si)泥浆>为Ti-6Al-4V投资扔的脸上衣的O3粉末和硅石大音阶的第五音被测量。Y-Si脸上衣系统做的壳的热行为被微分扫描热量计(DSC)调查,热gravimetric(TG)分析与集体spectrometry(MS)结合了,并且阶段转变被X光检查衍射(XRD)决定。热力量,剩余力量,线性扩大系数,和壳的穿的抵抗性能也被测试。微观结构和相互作用层的元素分发被分别地扫描电子显微镜(SEM)和精力散的分光计(版本)学习。microhardness测试者被申请microhardness。结果证明泥浆为至少60是稳定的?h。YZrO3的很小的数量低于1050被形成?普牯慭?楦汥?桴潥祲?畢?畯?敲?瑬?灡汰?畱污瑩瑡癩汥?潴愠眠摩牥挠慬獳漠?睴?楤敭獮潩慮?楤慬潴?牧癡瑩?桴潥楲獥?潆?慥档琠灹?景猠汯瑵潩獮眠?数晲牯?潨潬牧灡楨?敲潮浲污穩瑡潩?挠浯異吗??
简介:采用扩散偶实验方法研究Fe含量对Ti6Al4V合金显微组织和性能的影响。通过制作Ti6Al4V-Ti6Al4V20Fe扩散偶,在1000°C经600h扩散退火,在一个样品内获得具有连续成分梯度的合金。结合电子探针、扫描电镜和纳米压痕,确定Ti6Al4VxFe合金成分-组织-硬度的关系。当合金中Fe含量增加到5%(质量分数)时,时效状态下合金中的α相体积分数降低到55%,同时合金具有最高的硬度,Ti6Al4V5Fe合金将是Ti6Al4VxFe体系中最具前景的合金。HAADF-STEM和XRD结果表明,Ti6Al4V5Fe合金在固溶淬火阶段生成纳米尺寸α''层片,这些亚稳的α''层片在随后的时效过程中逐渐长大,并作为α相的形核核心,形成稳定α相。
简介:以便获得两高电镀物品迁居(他们)在高周波的表面的可靠性和罚款维的控制声学的波浪(锯)设备,4-layeredTi/Al-Mo/Ti/Al-Mo电极电影在128°Y-XLiNbO3上被调查由劈啪作响的底层免职。结果显示4-layered电影与常规Al-0.5wt.%Cu电影相比有改进他们可靠性。他们的一生比在5×的当前的密度测试的Al-0.5wt.%Cu电影的长约三倍107A/厘米2和200°C的温度。而且,4-layered电影容易在反应离子蚀刻被蚀刻,罚款维的控制为高周波的锯设备在模式复制期间被认识到。为4-layered电影,最佳瞬间数量和劈啪作响的参数为高他们可靠性是很重要的。
简介:Nb-24Ti-18Si-2Al-2Hf-4CrandNb-24Ti-18Si-2Al-2Hf-8Cralloyswerepreparedbyarcmeltinginawater-cooledcrucibleunderargonatmosphere.Microstructuralcharacteristicsandoxidationresistanceofthealloysat1250℃wereinvestigated.Theresultsshowthat,whentheCrcontentis4at%,themicrostructuresconsistof(Nb,Ti)_(ss)andNb_5Si_3;asCrcontentincreasesto8at%,C14LavesphaseCr_2Nbisformed.Theisothermaloxidationtestsshowthattheoxidationkineticsofthetwoalloysfollowsimilarfeatures.Theweightgainsofthetwoalloysafteroxidationat1250℃for100hare235.61and198.50mg·cm~(-2),respectively.Duringoxidation,SiO_2,TiO_2,Nb_2O_5andCrNbO_4areformedatfirst.Then,Ti_2Nb_(10)O_(29)isformedafteroxidationfor20minandbeginstochangeintoTiNb_2O_7astheoxidationproceeds.SiO_2isformedassolidstateatfirstbutlaterevolvesintoglassystatetoimprovethecohesionofthescale.Afteroxidationfor100h,oxidationproductsconsistofSiO_2,TiNb_2O_7,Nb_2O_5andCrNbO_4.
简介:TheeffectofAl-3Ti-0.2C-5Sr(wt%)grainrefinerontherefiningperformanceandmodificationofA356alloywasinvestigatedusingopticalmicroscope(OM).ThemorphologyandcrystalstructureofternaryAl-Ti-SrphasesinAl-3Ti-0.2C-5Srrefinerwereanalyzedbyscanningelectronmicroscopy(SEM)andtransmissionelectronmicroscopy(TEM).TheresultsshowthattheternaryAl-TiSrphasesinAl-3Ti-0.2C-5SrrefinercanpromotethegrainrefiningefficiencyofA356alloy.TheternaryAl-Ti-Srphasesco-existintwomorphologies,i.e.,blocky-likephaseandsurround-likephase,besides,whichbothhavethesamechemicalcompositionofAl_(34)Ti_3Sr.ThecrystalstructureofAl_(34)Ti_3Srisface-centeredcubic,andthelatticeparameterisdeterminedtobeabout1.52nm.
简介:BondingofAl2O3tocuisperformeddirectlyusingTifoilattemperatureof1273K.Themicrostructureofthejointinterfaceisinuestigatedthroughscanningelectronmicroscope(SEM),electron.probemicroanalysis(EPMA)andX-raydiffraction(XRD).theeffectoftheinitialtifoilthicknessonthereactionlayerthicknessandthejointStrengthareinvestigated.
简介:Al-5Ti-0.5C-8Sr(集体部分,%)主人合金用一个melt反应方法被准备。微观结构和主人合金的合成过程被光显微镜学,X光检查衍射,扫描电子显微镜学和X光检查调查精力散的光谱。结果证明主人合金由组成一(艾尔),TiAl3,TiC,Al4Sr和Al-Ti-Sr分阶段执行。主人合金的合成机制如下:TiAl3通过在K2TiF6和艾尔之间的反应被形成在基础材料的部分融化层融化在850个C粒子与同类地分布式的加强在超声的行动和一张契约下面被变成液体filler在团结以后被获得。体积部分原文如此,在契约的粒子能被改变以铜锌金焊接的温度改变。最大值原文如此,契约材料的粒子体积部分在brazi到达了37%?
简介:ArapidlysolidifiedAl-2.5Ti-2.5Fe-2.5Cr(massfractionin%)alloywaspreparedbymeltspinning.Asquenchedandas-annealedmicrostructureswerestudiedbyX-raydiffractometry(XRD),transmissionelectronmicroscopy(TEM),high-resolutiontransmissionelectronmicroscopy(HREM)andenergydispersivespectrum(EDS)analysis.Themicrohardnessofthealloyatdifferentannealingtemperatureswasmeasured.TheresultsobtainedindicatethatthemicrohardnessoftherapidlysolidifiedAl-2.5Ti-2.5Fe-2.5Cralloydoesnotvarywithdifferentannealingtemperatures.Theas-quenchedmicrostructureofthealloyincludestwokindsofdispersedprimaryphases:Al3TiandAl13(Cr,Fe)2.Afterannealingat400℃for10h,thestablephaseAl13Fe4appearsinthemicrostructure.
简介:Li1.3Al0.3Ti1.7(PO4)3pelletssinteredwithdifferentmolefractionsofLiBO2werepreparedbysol-gelmethod.Thestructuralidentification,surfacemorphology,ionicconductivity,andactivationenergyofthepelletswerestudiedbyX-raydiffraction,scanningelectronmicroscopy,andelectrochemicalimpedancespectroscopy.TheresultsshowthatalltheLi1.3Al0.3Ti1.7(PO4)3pelletssinteredwithdifferentmolefractionsofLiBO2havesimilarX-raydiffractionpatterns.ThesinteredpelletbecomesdenserandtheboundaryandcorneroftheparticlesbecomeillegiblewiththeincreaseofLiBO2.AmongtheLi1.3Al0.3Ti1.7(PO3)4pelletssinteredwithdifferentmolefractionsofLiBO2,theonesinteredwith1mol%LiBO2showsthehighestionicconductivityof3.95×10-4S.cm-1andthelowestactivationenergyof0.2469eV.
简介:Thecreepmechanismofas-castMg-6Al-6Ndalloywasstudied.Thestressexponentforcreepis5.8undertheappliedstressesof50-70MPaat175°C.Theactivationenergyforcreepis189kJ·mol-1undertheappliedstressof70MPaintherangeof150-200°C.Thetruestressexponentandthresholdstressforcreeparecalculatedas4.96and10.2MPa,respectively.Thetruestressexponentindicatesthatitscreepmechanismbelongstothedislocationclimb-controlledcreep,whichisinagreementwiththemicrostructurechangesbeforeandaftercreep.ThehighvalueforstressexponentisattributedtotheinteractionofAl11Nd3phasewithdislocations.Theactivationenergyismorethantheself-diffusionactivationenergyofMg,whichisattributedtotheloadtransfertakingplacefromthematrixtoAl11Nd3phaseduringcreep.
简介:Theelectronbeamwelding-brazingbeingusedtojoin5A06AlalloytoTC4Tialloydecreasestheformationofbrittleintermetalliccompound.Experimentswerecarriedouttostudytheinfluenceofelectronbeamweldingparametersonthetensilestrengthofwelds,basedonanorthogonaltestandanalysismethod.Theweldingparametersincludebeamcurrent,weldingspeed,scanningfigure,scanningfrequency,figuresize,beamoffsetandfocuscurrent.Theoptimumparametersfor3mm5A06Alalloyand2mmTC4alloywereasfollows:accelerationvoltagewas60kV,beamcurrentwas11mA,weldingspeedwas600mm/min,focuscurrentwas0mA,scanfigurewasO,scanningfrequencywas1000Hzandbeamoffsetwas0.5mm.Theresultsshowthatthejointswerewithgoodappearanceandqualityweldedbytheoptimumparameters.ThesuccessfuljointscouldbegainedandthemaximumtensilestrengthofAl/Tidissimilaralloyjointscouldbeupto222.61MPausingelectronbeamwelding-brazing.
简介:采用一种新型高通量实验方法,实现对Ti-5553合金(Ti-5Al-5Mo-5V-3Cr,质量分数,%)在600~700℃范围内的连续温度梯度热处理。实验通过对圆台形样品进行直流电加热,由于截面面积不同而导致电流热效应不同,从而使样品表面温度呈梯度变化。采用端淬实验实现Ti-5553合金的连续冷却速率变化,研究合金在不同热处理条件下的显微组织演变和力学性能。结果表明:Ti-5553合金的伪调幅分解温度为(617±1)℃,析出的α相尺寸在300nm左右;合金在伪调幅分解温度下时效4h达到最高的硬度。因此,这种高通量方法能够快速准确地判断合金中相转变温度以及相应的组织转变。
简介:TheeffectsofheattreatmentsonthephasetransformationbehaviorofTi49Ni49.5Fe1V0.5andTi48Ni48.5Fe1V2.5alloyswereinvestigated.TheresultsindicatethatthealloyssubjectedtodifferentheattreatmentshaveB2structureatroomtemperature.AllthespecimensexhibitatwostageB2→R→B190martensitictransformationoncooling,butaB190→B2one-stagereversemartensitictransformationonheatingexceptagedA1alloy,whichundergoesanabnormaltwo-stagetransformationuponheating.ThephasetransformationtemperaturesareaffectedbyheattreatmentsandVcontent,whichcanbeattributedtothevariationofthesecond-phaseparticlescontentinthematrix.
简介:Inthisstudy,C_f/AlcompositesandTiAlalloyswerejoinedbyanewmethodnamedlaser-ignitedselfpropagatingsynthesis(SHS).Mixedpowdersof63.0Ni-31.9Al-5.1Ti(wt%)wereusedasjoininginterlayer.Perfectjointwasgot.ThemicrostructureevolutionandformationmechanismoftheSHSjointwereinvestigatedbyscanningelectronmicroscopy(SEM),energy-dispersivespectroscopy(EDS)andX-raydiffraction(XRD).Resultsshowthatlocalizedmeltingoccursonbothsides.Oneγ-Ni_(0.35)Al_(0.30)Ti_(0.35)andtwoNi-Alreactionlayersform,respectively,intheTiAl/interlayerandC_f/Al/interlayerinterfaces.ThecombustionofNi-Al-TiinterlayerbeginswiththesharpreactionofNiandAl.TheinterlayerproductisaeutecticorganizationofNiAlandAl-richγ.