简介:NiobiumionimplantationisfoundtosignificantlydecreasethefrictioncoefficientandimprovewearresistanceofNiTishapememoryalloy.Scanningelectronmicroscope(SEM)observationsindicatethatsurfacegroovesformedonNiTiduringthemechanicalpolishingareremovedafterNbionimplantation.DryfrictiontestsshowthatNbimplantedNiTisamplesexhibitalowerfrictioncoefficient,narrowerweartracks,fewerweardebrisgenerated,46%–62%reductioninwearwidth,and29%–49%reductioninweardepthcomparedwiththeuntreatedNiTi.Wearresistanceisrelatedtotheincidentparameters,andtheNbimplantedNiTiwiththeincidentdoseof2.591017ionsácm-2,andincidentcurrentof2mAbehavesthebestwearperformance.ThelubricatingofNb2O5,goodoxidationresistanceofNbinNiTi,andincreasedmicro-hardnessofNiTiareresponsiblefortheenhancedwearresistance.
简介:MicrostructureandtextureofTi-Nb-Sibasedalloys,preparedbywaterquenchingfromβ-phasefield,coldrollingandrecrystallizationheattreatmentfollowedbywaterquenching,wereinvestigatedintermsofopticalmicrostructureandanalysisofX-raypolefigureresult.Inas-quenchedsample,relativelyrandomdistributionofpolefigurewasdetectedwithoutshowingaspecifictexturecomponent.Inas-coldrolledsample,however,itisfoundwell-developedseveraltexturecomponentsconsistingofrotatedcube,α-fiberandγ-fibertexturecomponentswhicharefrequentlyobservedinbcc-structuredmetalsandalloyswerefound.Therefore,texturecomponentsdevelopedinthepresentalloysarecloselyrelatedtothedeformationofβ-phaseeventhoughsmallamountofα″phaseco-existinthemicrostructure.Inrecrystallizedsample,α-fibertexturecomponentisweaklydetectedwhiletheothertexturecomponents,rotatedcubeandγ-fibercomponents,appearstoberelativelyunchanged.Noadditionaltexturecomponentsweredetectedbesidesthosetexturecomponentsobservedinthecoldrolledsamples.
简介:Nb-bearingslagfromBaotouhotmetalwaschlorinatedinthesolidstatewithmoltenCaCl2undervacuum,96~98%MnOorFeObeingthusvolatilized.Byreducingthechloridizedresidueunderadditionofflux,ferroniobiumwithabout60%Nbwassuccessfullymade.KineticstudyofchlorinationofsyntheticMnO-Nb2O5-SiO2andFeO-Nb2O5-SiO2slagsystemswasconducted,andanon-reactingcoremodelforthedemanganificationwithfreeuseofactivitywasformulatedandtherate-controllingstepwasexplained.
简介:多层的Nb2O5部nanoporous电影被控制阳极化过程成功地在包含4的乙烯乙二醇在Nb表面上综合?vol%HF并且2?vol%H2O2电解质。nanoporous电影被地排放扫描详细描绘电子显微镜学(FESEM),传播电子显微镜学(TEM),和X光检查衍射(XRD)。Nb2O5部nanoporous电影与~的方面墙厚度有多层的形态学5?nm,有~的一条直径的不规则的毛孔25?nm,并且一段多达7.39?m,取决于阳极化时间。为多层的Nb的机制<潜水艇class=“a-plus-plus”>2O<潜水艇class=“a-plus-plus”>5nanoporous形成也被讨论。这些nanoporous材料能在太阳能电池,煤气的传感器,催化剂,光过滤器,和电容器的地里是很有用的。
简介:InordertoimprovethehydrogenstoragepropertiesofLiBH_4-MgH_2composite,twodifferentkindsofNb-basedcatalysts,NbCandNbF_5,wereaddedtoLiBH_4-MgH_2compositebyballmilling,andtheeffectofcatalystsonhydrogenstoragepropertiesofthemodifiedLiBH_4-MgH_2systemwasinvestigated.TheexperimentalresultsshowthatLiBH_4-MgH_2compositeisatwo-stepdehydrogenationprocess,andNb-basedcompoundscanremarkablyenhanceitsdehydrogenationkinetics.Forthecompositewithoutadditionofcatalysts,thestartingdecompositiontemperatureforthefirstdehydrogenationstepisaround320℃,andthereisalongperiodofincubationtime(around220min)fortheoccurrenceoftheseconddecompositionstepevenathightemperatureof450℃.Itneedsmorethan10htocompletethedecompositionprocessandreleasearound9wt%H_2.Afteradditionof5mol%NbF_5,thestartingdecompositiontemperatureforthefirstdehydrogenationstepisaround150℃,thereisnoincubationtimefortheseconddecompositionstep,andittakesaround40mintocompletethesecondstepandreachesatotaldehydrogenationcapacityof9.5wt%.NbF_5hasbettercatalyticeffectthanNbC.Basedonthehydrogenation/dehydrogenationbehaviorsandstructuralvariation,themechanismofcatalyticeffectwasdiscussed.
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:Ti47Cu38xZr7.5Fe2.5Sn2Si1Ag2Nbx(x?=?0,1,2;at%)体积有优异简历腐蚀抵抗的金属性的眼镜(BMG)被铜模子扔综合。尽管到Ti-Cu-Zr-Fe-Sn-Si-AgBMG的Nb的次要的增加稍微减少形成眼镜的能力(GFA),忍受Nb基于Ti的合金能是在体积的casted有直到3的直径的玻璃质的杆形式?公里。有Nb的Cu的部分替换在提高基于Ti的BMG的简历腐蚀抵抗上是有效的,这被发现。Potentiodynamic极化大小证明基于Ti的BMG的Nb增加导致更高开电路的潜力和pitting潜力以及更低的被动电流在丝等的密度答案。电气化学的阻抗光谱学(EIS)结果显示与Nb内容增加,基于Ti的BMG的费用转移电阻价值变得更大,证明表面氧化物电影是更保护的。忍受Nb基于Ti的BMG也展出在比得上Ti-6Al-4V的vitrobiocompatibility好合金。提高的简历腐蚀电阻,在vitro优秀biocompatibility和忍受Nb基于Ti的BMG的好机械性质为生物医学的应用是有利的。
简介:Nb-Ti-Si-based合金粉末被元素的粒子的机械alloying(麻省)准备。形态学,尺寸,阶段成分,雏晶尺寸,格子紧张,作文和内部微观结构的进化,等等,合金,粉末被X光检查衍射(XRD)分析,扫描电子显微镜学(SEM),精力散的光谱学(版本),激光粒子尺寸分析器和传播电子显微镜(TEM)分析。合金粒子逐渐地被精制,他们的形状随milling时间的增加变得球状。Nb稳固的答案(Nbss)的衍射山峰分阶段执行移动向从2~5在球milling期间降低2个角度?h,并且在那Nbss衍射以后,山峰变向更高,有milling的增加的2个角度从5~70预定?h,它主要由于alloying元素原子的溶液被归因于Nbss粉末的格子参数的改变进Nb格子形成Nbss。在球milling过程期间,在雏晶尺寸的减少和粉末导致他们的衍射的连续拓宽的Nbss的格子紧张的增加达到顶点。典型薄片状的微观结构为5在球milling以后在粉末粒子内被形成?h并且变得更多随milling时间的增加精制了并且一致。在40-h-ballmilling以后,典型薄片状的微观结构消失并且很同类的微观结构相反被形成。这同类的微观结构被证明由仅仅使过饱和的Nbss阶段构成。
简介:研究烧结温度对含Mn-Nb-Tb的Zn-V-O基陶瓷显微组织和压敏性能的影响。结果表明,随着烧结温度由875°C升高到950°C,烧结陶瓷样品的密度由5.55g/cm3降低到5.45g/cm3,其平均晶粒尺寸由4.1μm增大至8.8μm,击穿场强由7443V/cm显著降低至1064V/cm。经900°C烧结的压敏陶瓷样品具有明显的非线性特性,其非线性系数为49.4,漏电流密度为0.21mA/cm2。当烧结温度由875°C升高到950°C时,Zn-V-O基陶瓷样品的介电常数由440.1增大到2197.2,其损耗因数的变化范围为0.237-0.5。因此,本研究中Zn-V-O基陶瓷组分和烧结条件有利于以银为内电极的先进多层芯片压敏电阻的开发。
简介:通过微弧氧化法在新型医用近β钛合金Ti-3Zr-2Sn-3Mo-25Nb表面制备一层含Ca、P多孔薄膜,再将其在胺基化溶液中活化处理以在薄膜表面引入NH-2。借助XRD、SEM和EDS研究该多孔复合薄膜的组成和表面形貌,并通过模拟体液浸泡实验、体外细胞培养实验和动物体内植入实验研究经上述表面改性处理后的Ti-3Zr-2Sn-3Mo-25Nb合金的骨诱导活性。结果表明:该薄膜主要由金红石型TiO2和锐钛矿型TiO2组成,是一种含有Ca、P的陶瓷混合物;薄膜在模拟体液中具有很好的生物活性,成骨细胞能够很好地在薄膜上分化、生长;表面覆膜处理的Ti-3Zr-2Sn-3Mo-25Nb合金的体内骨诱导活性优于未处理的Ti-3Zr-2Sn-3Mo-25Nb合金的。