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  • 简介:BondingofAl2O3tocuisperformeddirectlyusingTifoilattemperatureof1273K.Themicrostructureofthejointinterfaceisinuestigatedthroughscanningelectronmicroscope(SEM),electron.probemicroanalysis(EPMA)andX-raydiffraction(XRD).theeffectoftheinitialtifoilthicknessonthereactionlayerthicknessandthejointStrengthareinvestigated.

  • 标签: ALUMINA active BRAZING INTERFACIAL reaction joint
  • 简介:铝和铬的性质有不少相似之处.它们都是两性金属,既能溶于酸又能溶于强碱;都被冷的浓硝酸钝化,其氧化物Al2O3、Cr2O3都是熔点高、硬度大的物质,其氢氧化物Al(OH)3、Cr(OH)3都是难溶于水的两性氢氧化物,既能溶于酸又能溶于强碱.本文利用Al—H2O系统的(?)—pH图及Cr—H2O系统的(?)—pH图,对铝和铬及其氢氧化物的两性进行分析.一、Al—H2O系统(?)—pH图图1为Al—H2O系统的(?)—pH图,其作法是:(?)线代表H+/H2线.根据(?)(H+/H2)=-0.0592pH-(0.0592/2)1g(P(H2))

  • 标签: 两性金属 两性的 AL CR OH 图图
  • 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.

  • 标签: Al-Ti-Fe-Cr合金 微结构 热稳定性
  • 简介:Ti6Al4Visawidelyappliedinmedicalimplantssuchasbone,joint,andteethduetoitsexcellentmechanicalproperties,corrosionresistance,plasticityandthebiocompatibilityofthesurfaceoxide.However,thenativesurfaceoxidefilmisquitethin(about5nm)andtechniquessuchasmicroarcoxidation,plasmasprayedhydroxyapatitaeandplasmaimmersionionimplantationareusedtosynthesizethickersurfacetitaniumoxide.

  • 标签: 微弧氧化 生物活性 TI6A14V 氧化钛保护膜 金属材料
  • 简介:ItwasshownbyTEMandX-rayanalysisthatNi3AlisthemainphaseoftheintermetallicsynthesizedundercompressionfromthepowdermixtureofNiwithAlalloyedbyB.TheNi3Bisasecondaryphase.ThevalueofthelatticeparameteroftheintermetallicNi3AlwithandwithoutBincreaseswhentheconcentrationofAlincreases.TheincreaseinAlconcentrationfrom23.5to25.0intheinitialpowdermixtureleadstodecreasingthesolubilityofBintheNi3Alphase.

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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.

  • 标签: 锌铝共晶合金 Al2O3p/6061Al化合物 湿润 界面微结构 焊接技术
  • 简介:Inthispaper,X-raydiffractogramanalysisandSEMobservationofAl4C3formedathightemperaturefromcarbon-containingrefractorieswithAlhavebeencarriedout.Aluminumaddedtocarbon-containingrefractoriesreactswithC(s)toformAl4C3(s)graduallyduringheatingfrom600℃to1200℃.ItisconsideredthattheinterlockedstructureofAl4C3platecrystalspromotestheoutstandingincreaseofhotmodulusofruptureofcarbon-containingrefractorieswithAl.TheHMORofcarbon-containingrefractoriesaddedwithAladditivefrom0to5wt%increasesby2.8timesbeingfrom6.5MPato18.2MPa.AfterathermochemicalcalculationforhydrationreactionprocessesofAl4C3andH2O(g),theequilibriumpartialpressurechartofH2O(g)inH2O-Al4C3-Al(OH)3systemvsvarioustemperatureshasbeenattained.TheH2O(g)partialpressureintheairneededfortheAl4C3hydrationreactionisnomorethan10~18atmatthetemperaturebelow120℃.Itisconsideredthattheburnedcarbon-containingrefractorieswithAlisextremelyeasytohydrateandthecrackingofburnedcarbon-containingrefractoriesisgeneratedbecausethatthehydrationexpansionis2.11timesduringtransformingfromAl4C3toAl(OH)3.ThefundamentalmeasureagainsthydrationoftherefractoriesistoinsulatetherefractoriesfromH2O(g)byvariousmeanssuchaspitchimpregnationorothersealingmaterials.

  • 标签: 碳化铝 水合作用 耐火材料 SEM 热化学分析
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  • 简介:关于Al(OH)3沉淀问题常见三大类:第一类是OH^-与Al^3+液相混合;第二类是H^+和AlO2^-液相混合;第三类是Al^3+与AlO2^-液相混合。

  • 标签: 解法 沉淀问题 AL(OH)3 数形结合 中学 化学
  • 简介:Howtocontrolmeltcompositionisthekeyforgettinghighqualityalloymelt.Thepapermadethefollowingefforts:(1)TheactivitycoefficientsinTi-15-3melthavebeencalculated.(2)Takingadvantageoftheactivitycoefficients,theevaporationlossesofcomponentsinTi-15-3meltduringISMprocesshavebeenstudied.Thecalculatedresultsshowthatthereisacriticalvacuumdegree(about1.33Pa)duringmeltingprocess.

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  • 简介:针对Ti-15-3环板零件的形状特点,分析了成型工艺的几种可能性,说明了翻孔成型的优点.详细介绍了钛合金环板翻孔成型工艺过程,对成型中遇到的工艺技术难题提出了解决办法,如工艺参数的选取、成型模具的结构设计及零件回弹量的确定方法等.对此类零件的成型生产具有一定的借鉴作用.

  • 标签: Ti-15-3板 翻孔成型