简介:研究冷轧和后续退火形变热处理对Ni50Ti50形状记忆合金超弹性行为的影响。采用铜坩埚真空感应熔炼法制备样品。将成分均匀的样品进行热轧后在900°C退火,然后再进行冷轧,冷轧后样品的厚度有不同程度的减少,最大可达70%。透射电镜检测结果显示严重的冷轧导致Ni50Ti50合金中形成了纳米晶和非晶的复合显微组织。400°C下退火1h后,冷轧样品中的非晶发生晶化形成纳米晶组织。随着冷轧变形量的增加,在超弹性实验中Ni50Ti50合金的弹性应变增加,变形量为70%的冷轧-退火样品其弹性应变为12%。此外,随着变形量的增加,应力诱导马氏体相变的临界应力提高。值得注意的是,70%变形量的冷轧-退火样品的阻尼容量值为28J/cm3,明显高于商业NiTi合金。
简介:Surface-graftedpoly(ethyleneglycol)(PEG)moleculesareknowntopreventproteinadsorptiontothesurface.NitinolsampleswerecoatedundertetraglymeECRcoldplasmaconditionstoenhanceitsbiocompatibility.ThemodifiedNitinolsurfaceswerecharacterizedbyhighresolutionESCAandcontactangle,itwasdemonstratedthatthedepositedPEG-likecoatingswerebuiltupmainlyof-CH2-CH2-O-linkagesinsurfaces.ThesurfacewettabilityofthemodifiedNitinolwasincreasedcomparedwiththecontrolsurface.HumanplasmaproteinwasadsorbedonNitinolevaluatedbySEM,theproteinadsorptiononmodifiedsurfacesdecreasedrapidly.Thus,thepotentialbenefitsofcoldplasmatechniquewillbeofusetothebiomedicalindustriesimprovingthebiocompatibilityofmetals.
简介:NiTialloyisproducedbymechanicalalloying(MA).Itbecomesamorphousaftermillingforenoughtime,suchas100hinthispaper.DSCmeasurementshowsthatthecrystallizationtemperatureis676Kfortheamorphouspowder.Activationenergyofcrystallizationis199.98kJ/molforMApowder,whichislowerthanthatofamorphouspreparedbymagnetronsputtering.Avramiparameterofcrystallizationis1.07.
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:Themicrostructureofstress-inducedmartensite(SIM)inthenanocrystallineNiTialloywasinvestigatedbymeansoftransmissionelectronmicroscopy(TEM).Theresultshowsthatthemulti-variantstructureofthemartensiteissuppressedandonlysingle-variantmartensitictwinsformaftertensiledeformationwhenthegrainsizeissmallerthan80nm.Thenormaldirectionsofthe(001)B190twinplanesareallwithintherangeof45°fromtheaxialdirectionofthewire.Theanglebetweentwincrystals(1'11)Mand(111)ToftheSIMisalsofoundtobesmallerthanthatofthermallyinducedmartensiteinnanocrystallineNiTi.
简介:最近的实验[1]在superelastic的导致压力的阶段转变揭示了宏观的领域模式的许多新现象多晶的NiTi试管在张力的装载期间。新现象与一个螺旋状的领域,到柱体的从螺旋的领域拓扑学转变,域前面分叉和领域模式的负担路径依赖的形成包括变丑不稳定性。在这份报纸,我们与nonconvex种类精力作为有弹性的连续统为多晶体建模[2]并且采用非局部的种类坡度精力说明散开的领域前面的精力。我们在由一个非局部的有限元素方法的张力的装载下面在试管模仿平衡领域模式和他们的进化(女性)。域模式的观察负担路径依赖和拓扑学转变由于试管系统的热力学的metastability,这被揭示。计算也证明试管墙厚度在领域模式上有重要效果:与固定材料性质和界面的精力密度,大试管墙厚度导致一个长、细长的螺旋状的领域并且圆柱域的前面的严重分叉。
简介:[篇名]InfluenceofWCadditionanmicrostructuresoflaser-meltedNi-basedalloycoating,[篇名]MicrostructureanddryslidingwearbehavioroflasercladNi-basedalloycoatingwiththeadditionofSiC,[篇名]PreparationofAdvancedLithiumSecondaryBatterieswithTin-IronAlloyPlatingAnodesandTheirCharge-DischargeBehaviors,[篇名]SnAg-alloycoatingforconnectorsandsolderingapplications,[篇名]Structureandpropertiesofwear-resistanttitaniumcarbonitride-basedcoatings,[篇名]TheanalysisofthedepositionmechanismofZn/NialloyplatingusinganEQCM,[篇名]Theeffectofheattreatmentonwearresistanceofpartshavinghard-alloycoating.
简介:AdvancedLithiumSecondaryBatteriesUsingTin-IronAlloyNegativeElectrodesPreparedbyElectroplating;CavitationerosionofTi-Nishapememoryalloycoating;Effectsoffueldyeonthehotcorrosionresistanceofmarinegasturbinematerials;EffectsofphosphorouscontentsandambienthumidityonthefrictionandwearpropertiesofNi-W-PalloyplatingFrictionandwearofelectrolessNialloyplatedgearundernon-lubricationconditioninhighvacuum
简介:五峰合金有限责任公司是在五峰铁合金厂的基础上,由湖北天宇电业集团控股、县财政局、员工持工基金会共同出资于一九九八年初组建的有限责任公司。公司注册资本金800万元,现有资产总值1700万元,企业员工人数280名,其中,大中专毕业生41名,专业技术人员43名,党员18名,拥有3200KVA硅铁电炉2台,1000KVA和630KVA硅钙电炉各2台,形成了年生产硅铁4400吨、硅钙1000吨的生产能力,
简介:ACOUPLEDMACRO-MICROSIMULATIONFORTHEPREDICTIONOFMICROSTRUCTUREOFALALLOYCASTINGS,AstudyonporositydistributionofA356aluminumalloycastings,Diagnosisofoxidcfilmsbycavitationmicro-jetimpact,Effectofflyash(asanadditivetogreensand)onthesurfaceroughnessofAl-7%SialloycastingsusingTaguchiTechnique,EffectofSolidificationTimesonCrackOpeningDisplacementofAluminumAlloyCastings,EvaluationofinversesegregationinCu-8mass%Sialloyingotwithvisiblelightspectroscopy.