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77 个结果
  • 简介:通过拉伸试验、晶间腐蚀与应力腐蚀实验,结合金相观察和高分辨透射电镜分析,研究微量Ti和Cr对Al-Zn-Mg-Cu-Zr合金弥散相、再结晶与性能的影响。结果表明:在Al-Zn-Mg-Cu-Zr合金中,添加0.04%Ti(质量分数,下同)可使合金抑制再结晶的能力降低,从而导致合金的力学性能和抗应力腐蚀性能降低;复合添加0.04%Ti和0.04%Cr,形成含有少量Cr的Al3(Zr,Ti)弥散相,合金抑制再结晶的能力显著增强,合金在保持高强度的同时,抗应力腐蚀性能显著提高,抗拉强度为687.6MPa,屈服强度为651.4MPa,比不含Ti和Cr的合金分别提高15.3MPa和7.8MPa,应力腐蚀裂纹萌生时间由161h延长至306h。

  • 标签: AL-ZN-MG-CU-ZR合金 再结晶 应力腐蚀 力学性能
  • 简介:Inthiswork,asimpleandfacileone-potoleylaminesolvothermalsyntheticmethodwasdevelopedtosynthesizeCu_2ZnSnS_4(CZTS)nanocrystals.AndtheCu_2ZnSn(S,Se)_4(CZTSSe)thinfilmswerepreparedbyselenizingCZTSnanocrystals.TheobtainedCZTSnanocrystalsandCZTSSefilmswerestudiedusingX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),scanningelectronmicroscopy(SEM),energy-dispersiveX-rayspectroscopy(EDX),andultraviolet–visiblespectrophotometer(UV–Vis).TEMresultsshowthatthesphere–likeCZTSnanoparticleswithdiameterbetween12and35nmarepolydispersed.XRDstudiesindicatethatthepreparedCZTSnanocrystalsformkesteritecrystalstructure,andtheCZTSSefilmswithkesteritecrystalstructurearealsoobtainedattheannealingtemperaturesof500and550°C.Inparticularafterannealingat500°Cfor20min,theCZTSSefilmexhibitsasmooth,uniform,crack-free,andlarge-grainedtopographyandpossessesCu-poorandSn-richcomposition.Moreover,itshowsstrongopticalabsorptionfromvisibletonear-infrared(IR)region,anditsopticalbandgap(Eg)isfoundtobeabout1.44eV.

  • 标签: 薄电影 Oleylamine solvothermal 水晶结构 CZTS nanocrystals
  • 简介:采用纯Al片表面浸Zn后再电镀厚Cu层的方法制备Cu/Al层状复合材料。在473~673K温度范围内对该复合材料进行退火,研究退火过程中Cu/Al界面扩散与反应、界面金属间化合物(IMCs)层的长大动力学以及Cu/Al层状复合材料电阻率。结果表明,经过473K、360h的退火处理,未观察到Cu.AlIMCs层,显示Zn中间层能有效抑制Cu/Al界面扩散。可是,当复合材料经573K及以上温度退火时,Zn层中的Zn原子主要向Cu中扩散,从Al侧到Cu侧形成CuAl2/CuAl/Cu9Al4三层结构的反应产物。IMC层遵循扩散控制的生长动力学,Cu/Al复合材料的电阻率随退火温度及时间的增加而增大。

  • 标签: Cu.Al金属间化合物 层状复合材料 电镀 界面反应 生长动力学 电阻率
  • 简介:摘要;本设计采用电感耦合等离子发射光谱法(ICP—OES)对岩石样品中的Cu,Pb,Zn,Mn,Ni进行了测定,样品用四酸()熔矿,不经分离杂质,即可直接测定。该方法选择Cu,Pb,Zn,Mn,Ni的测定分析波长分别为324.7nm,220.3nm,202.5nm,257.6nm,221.6nm分析了用HCl提取与用王水提取,样品首先经磨样机碎至200目,用去离子水湿润后,用四酸熔矿,再将坩埚放置恒温电热板上加热,最后分别用王水或盐酸提取再定容,对其中的Cu,Pb,Zn,Mn,Ni做探究实验。

  • 标签: ICP,岩石,铜铅锌锰镍
  • 简介:Theadsorptionandelectronicpropertiesofisolatedcobaltphthalocyanine(CoPc)moleculeonanultrathinlayerofNaClhavebeeninvestigated.High-resolutionSTMimagesgiveadetailedpictureofthelowestunoccupiedmolecularorbital(LUMO)ofanisolatedCoPc.ItisshownthattheNaClultrathinlayerefficientlydecouplestheinteractionofthemoleculesfromtheunderneathmetalsubstrate,whichmakesitanidealsubstrateforstudyingthepropertiesofsinglemolecules.Moreover,strongdependenceoftheappearanceofthemoleculesonthesamplebiasintheregionofrelativelyhighbias(>3.1V)isascribedtotheimagepotentialstates(IPSs)ofNaCl/Cu(100),whichmayprovideuswithapossiblemethodtofabricatequantumstoragedevices.

  • 标签: STM图像 NACL 酞菁钴 状态 分子轨道 介导
  • 简介:Asamemberof1Dnanostructuredmaterials,theferromagneticandnonmagneticmultilayernanowiresexhibittremendouspotentialapplicationsinmanyfieldsduetotheiruniquemagneticandelectricalproperties.Thebasicpropertyofmultilayernanowirearrays,suchascoercivity,iscrucialimportantforthefutureapplication.Inordertoobtainthecoercivityinformation,besidesdirectlymeasuringitthroughexperiment,theoreticalcalculationalsoprovidesausefulandfastwaytoevaluatethemultilayer’scoervicity.Fig.1(a)and(b)demonstrateasinglemultilayernanowireandnanowirearraysembodiedinamatrix,respectively.Inthiswork,byimprovingPant’smodel,wedevelopedthenewmodelandsuccessfullypredictedtherelationshipbetweenthecoercivitychangingofCu/Nimultilayernanowirearraysandstructualparameters.Fig.

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  • 简介:PhasesandmicrostructuresofthreehighZncontainingAl–Zn–Mg–Cualloyswereinvestigatedbymeansofthermodynamiccalculationmethod,opticamicroscopy(OM),scanningelectronmicroscopy(SEM)energydispersivespectroscopy(EDS),X-raydiffraction(XRD),anddifferentialscanningcalorimetry(DSC)analysis.TheresultsindicatethatsimilardendriticnetworkmorphologiesarefoundinthesethreeAl–Zn–Mg–Cualloys.Theas-cast7056aluminumalloyconsistsofaluminumsolidsolution,coarseAl/Mg(Cu,Zn,Al)2eutecticphases,andfineintermetalliccompoundsg(MgZn2).Bothofas-cast7095and7136aluminumalloysinvolvea(Al)eutecticAl/Mg(Cu,Zn,Al)2,intermetallicg(MgZn2),andh(Al2Cu).Duringhomogenizationat450°C,fineg(MgZn2)candissolveintomatrixabsolutely.Afterhomogenizationat450°Cfor24h,Mg(Cu,Zn,Al)2phasein7136alloytransformsintoS(Al2CuMg)whilenochangeisfoundin7056and7095alloys.ThethermodynamiccalculationcanbeusedtopredictthephasesinhighZncontainingAl–Zn–Mg–Cualloys.

  • 标签: 铝锌镁铜合金 锌铝 显微组织 金属间化合物 扫描电子显微镜 差示扫描量热法
  • 简介:第三的Ni-5%Cu-5%Sn和Ni-10%Cu-10%Sn合金的液体状态undercoolability和水晶生长动力学被玻璃fluxing方法调查。在这二合金,304K的试验性的最大的undercoolings(0.18TL)和286K(0.17TL)被完成,树枝状的生长速度分别地达到39.8和25.1m/s。从进equiaxed结构的粗糙的树突的形态学的转变发生并且谷物尺寸(Ni)当undercooling增加时,显著地分阶段执行减少。格子常数和microhardness与undercooling的改进显然增加。Cu和Sn溶质内容的丰富减少树枝状的生长速度,当时提高格子常数和microhardness(Ni)阶段。

  • 标签: 三元铜镍锡合金液态 undercoolability 晶体生长动力学
  • 简介:AnefficientprocessfortheconversionofdimethyloxalateintoethyleneglycolwithhighselectivityandhighyieldoverCu2Owasinvestigated.InsituformedCuasatruecatalyticallyactivespeciesshowedagoodcatalyticperformanceforDMOconversiontoproduceEGin95%yield.

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  • 简介:Forthedevelopmentofalow-melting-pointfillermetalforbrazingaluminumalloys,aseriesofAl-Si-Cu-(Ni,Sn,Zn)fillermetalshavebeenstudied.Throughdifferentialthermalanalysis(DTA),themeltingtemperaturesofsuchAl-Si-Cu-(Ni,Sn,Zn)fillermetalsweredetermined.Theresultsshowthattheadditionof3wt.%-5wt.%SnintotheAl-6Si-15Cufillermetalcausesitssolidustemperaturetodecreasebyabout12℃.ThefillermetalwiththecompositionAl-6Si-l5Cu-2Niisproposed,whichpossessesameltingtemperaturerangeof512℃to520℃andamicrostructarethatincludesanAl-Cueutecticphases,Al-Si-Cueutecticphases,siliconparticlesandCu_2Al,AlNi_3,Al_7Cu_4NiandAl_3Ni_2intermetalliccompounds.Anadditionof5wt.%-7wt.%ZnintosuchAl-Si-Cufillermetalscausetheirsolidustemperaturestodropfurthertoavaluelowerthan498℃.MetallographicobservationsindicatethattheadditionofZnintotheAl-Si-CufillermetalinhibitstheformationoftheAl-Si,Al-CuandAl-Si-Cueutecticphases.TheremainingphasesareaAl_2Cuintermetalliecompound,anα-Alsolidsolutionandsiliconparticles.

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  • 简介:综合分析了Sn-Cu-Ni系无铅钎料的国内外研究现状,概述了Sn-Cu-Ni系无铅钎料的润湿性、微观组织、界面反应、力学性能、焊点可靠性、物理性能等性能特点。从钎焊工艺、添加微量元素等方面阐述了Sn-Cu-Ni系钎料各项性能的影响因素,并对Sn-Cu-Ni系钎料的应用前景和研究方向进行了展望。

  • 标签: 无铅钎料 润湿性 微观组织 界面反应
  • 简介:精密零部件进行真空扩散连接时,主要的扩散工艺参数对材料表面质量会有重要影响。以镜面无氧铜(Cu)为对象,改变保温温度和保温时间分别研究了这些因素对其表面质量的影响。结果表明,若保温时间均为60min,则加热温度越高,其表面晶界越清晰,且粗糙度亦有不同程度增加,而当加热温度达到800℃,其晶粒粗化,部分大晶粒内部出现孪晶和滑移带,表面粗糙度增加了11.2nm。此外,若将加热温度控制为450℃,则保温时间越长,表面粗糙度越大,但当保温时间超过180min后,表面粗糙度的增加量开始减小,然而最终会趋于稳定,为4.0nm左右。

  • 标签: 扩散连接 镜面Cu 表面粗糙度 加热温度 保温时间
  • 简介:Cracksmayeasilyoccurinthefusionweldbetweenvanadiumalloysandstainlesssteelduetothebrittleintermetallicsandweldingstress.Thehighvacuumelectronbeambraze-weldinghasbeensuccessfullyusedtojoinvanadiumalloy(V-5Cr-5Ti)tostainlesssteel(HR-2)withelectroplatedCuandAgcoating.Toinvestigatetheeffectsofelectroplatedcoatingontheweldability,thejointappearance,themicrostructureandthemechanicalpropertiesofthejointshavebeenthoroughlyanalyzed.Theresultsshowthatthejointsurfaceconfigurationwasgoodandrootreinforcementwasfullandsmooth.Areactionzone(RZ)wasgainedontheinterfacebetweentheVSCrSTialloyandHR-2stainlesssteelbasemetals.Thewidthofreactionzoneatthetopofthejointwasupto0.65mm,widerthanthatinthebottomofthejoint(0.46mm).Thereactionzoneconsistedofconsiderablysmallerdendriticstructureswithanaveragegrainsizeoflessthan10μm.ElementAgandCualmostenrichedtheinterfacebetweenV-5Cr-5TialloysubstrateandRZ,servingasaphysicalbarrierwhichdecreasesoravoidstheformationofintermetallics.Themaximumtensilestrengthofvanadiumalloy/stainlesssteeldissimilaralloyjointwasmorethan300MPa.Thejointwasdefectsfree.

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  • 简介:StraightandBentnano-cantileverspecimensarerespectivelyproposedtoinvestigatethesingle-modeandmixed-modecrackinitiationattheCu/Siinterfaceedgeinnanoscalecomponents.Withaminuteloadingapparatus,allnanoscalesamplesareinsituloadedandobserved.Numericalanalysisisemployedtoacquirethecriticalinterfacialstressdistributionsduringcrackinitiation.ThestressconcentrationregionsneartheedgeofCu/Siinterfaceinallspecimensarewithinthescaleof100nm,andthecriticalnormalandshearstresseshaveacircularrelationinnanoscalecomponents,whichrepresentsthefracturecriterionoftheinterfaceinnanoscalecomponents.

  • 标签: NANOSCALE 伸臂 接口 裂缝开始 混合模式 薄电影
  • 简介:针对无铅锡钎料润湿性的影响因素,通过对无铅锡钎料(5n99.3Cu0.7)在同一钎焊时间不同钎焊温度下以及同一温度不同钎焊时间的润湿性的研究(试验温度在推荐的最佳钎焊温度范围内),得出温度和钎焊时间对无铅锡钎料(Sn99.3Cu0.7)的润湿性的影响趋势。研究结果表明:钎焊温度升高、钎焊时间延长,可不同程度提高润湿力。

  • 标签: Sn99.3Cu0.7 无铅锡钎料 润湿性 填缝性 表面张力
  • 简介:新奇结合的聚合物,poly(1),在主要的链包含thiourea一半经由联合反应的铃木被综合。亚铜的离子的增加熄灭荧光(1)而荧光在另外的金属离子的增加之上稍微变化,poly展出荧光灯向Cu+察觉到能力的几乎转弯。当氢过氧化物被加到poly包含的答案(1)和Cu+,Cu时,+被氧化进导致荧光恢复的Cu2+,。H2葡萄糖oxidase(上帝)免除葡萄糖氧化的O2也恢复了荧光poly(1)/Cu+答案。结果显示(1)poly,/Cu+答案能为氢过氧化物和葡萄糖用作一个察觉到的平台。

  • 标签: 荧光化学传感器 共轭聚合物 过氧化氢 铜离子 葡萄糖 硫脲
  • 简介:以溶胶-喷雾干燥-热还原制备的纳米晶W-Cu复合粉末为原料,通过球磨改性、叠层压制和一步液相烧结分别制备3种两层梯度复合细晶W-Cu材料(W-10Cu/W-30Cu,W-20Cu/W-30Cu和W-30Cu/W-50Cu),对其致密度、组织成分特征及界面结合性能进行研究与分析。结果表明:3种梯度材料各均质层都达到高致密(相对密度〉98%);梯度材料具有明显的梯度组织,界面结合完好,Cu相呈连续网状结构,包裹在均匀分布的细小W晶粒周围;成分呈阶梯式变化,各层成分因Cu相的迁移和流失与初始设计值有一定的偏差;材料力学性能呈现梯度性,界面显微硬度处在两层显微硬度之间,结合强度高于各自富Cu层的拉伸强度,表明纳米复合W-Cu功能梯度材料各成分层之间有着优良的结合性。

  • 标签: 纳米W-Cu 梯度材料 致密性 成分变化 界面结合性 结合强度
  • 简介:Inrecentyears,themagneticmultilayerednanomaterialshavebeenextensivelystudiedforelectronics[1],ultrahightensilestrength[2],highstoragemedia[3],andmicrowavedevices[4]sincethegiantmagnetoresistance(GMR)effectwasfoundin1988.Asamemberof1Dnanostructuredmaterials,theferromagneticandnonmagneticmultilayernanowiresalsoexhibittremendouspotentialapplicationsinmanyfieldsduetotheiruniquemagneticandelectricalproperties.Inthiswork,theCu/NimultilayernanowirearraysarepreparediniontracktemplatewithelectrodepositionmethodandanewfacilemethodisfirstintroducedtoeasilyconfirmthedifferentlayerthicknessandcomponentbyremovingthenonmagneticlayerofCu.

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