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:在密度以内的第一原则的计算功能的理论被执行了在Ti32阶段>艾尔基于合金,Zr,Hf,和Sn(6.25at%)元素做了。格子常数,全部的精力和有弹性的常数为supercells被计算。形成热含量,体积模量,砍模量,幼仔模量,和内在的坚硬被调查。做的2阶段的韧性被Cauchy压力,G/B和泊松比率分析。结果证明由由Sn的艾尔(2n)的Zr,Hf,和替换的Ti(6h)的替换能使做的2阶段更稳定。2阶段的刚性和坚硬能被与Zr和Hf做提高,当Sn带相反的效果时。Sn是更强大的比Hf改进做的2阶段的韧性,但是Zr能增加易碎物。状态(DOS和PDOS)的密度和差别费用密度被获得揭示alloying元素的效果的内在的机制。
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: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.
简介:来临三维(3-D)打印了技术在设定的多孔的钛(Ti)的制造提供大可能性植入。然而,打印Ti的bioinert性质提出一个突出的问题。混合微弧的氧化并且热水(MAO-HT)多孔的金属上的处理能生产multi-scaled层次矫形植入,为3-D的表面修正的出现大潜力打印了植入。在这研究,有毛孔的圆柱的多孔的Ti6Al4V(Ti64)脚手架640缩放吗??
简介:纵的张力的性质原文如此有不同纤维体积部分的f/Ti-6Al-4Vcomposites被蒙特卡罗2-D模仿有限元素模型。纤维力量的随机的分发被二参数的Weibull功能表示。同时,接触元素和出生死亡元素被用来在debonding和纤维破裂以后描述界面的滑动过程(或矩阵裂开)分别地,它被子程序认识到在ANSYS-APDL(ANSYS参量的设计语言)应允了。试验性的结果证明收益应力和最终的张力的强度原文如此有增加的f/Ti-6Al-4Vcomposites增加纤维体积部分,当他们的相应紧张只是时相反。另外,几乎,一样的失败模式被获得在原文如此有各种各样的纤维体积部分的f/Ti-6Al-4Vcomposites什么时候界面砍力量被修理。最后,张力的力量由有限元素预言了分析与由全球分享负担的模型,预言了那相比本地人分享负担的模型和混合物的常规统治,因此画结论那个本地分享负担的模型为最终的张力的力量的预言是很完美的。
简介:这个工作的目的是用电气化学的技术,光显微镜学,扫描电子显微镜学(SEM),和精力与氟化物离子在酸的人工的口水为牙齿的应用学习Ti-6Al-4V合金的降级行为散的spectrometry(版本)。试验性的结果证明那个氟化物离子在Ti-6Al-4V合金的降级上有重要影响,并且有氟化物离子(大约0.1wt%)的明显的批评集中。与增加氟化物离子集中,腐蚀潜力(E合金的corr)移动了向否定并且同时,合金的阻抗减少了到严重pitting腐蚀的从最小的腐蚀的显著转变在跟随TiO2的溶解的合金表面上被观察被动电影,导致合金的腐蚀抵抗的减少。TiO2的电气化学的溶解被动电影包含了氟化物原子的亲核的攻击到TiO2的钛原子。另外,在酸的口水的Ca2+和Na+可以包含表面反应并且使反应更复杂。
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简介:Inthisstudy,inordertoevaluatetheperformanceofhomogenizedbauxite,twoAl_2O_3-SiC-Ccastableswerepreparedusinghomogenizedbauxiteandbrownfusedcorundumasaggregates,respectively.5mass%andalusitewasintroducedintothetwocastablessoastoresearchtheeffectandmechanismofandalusiteinAl_2O_3-SiC-Ccastables.Theresultsshowedthat:(1)comparedwiththebrownfusedcorundumbasedcastables,thehomogenizedbauxitebasedcastableshadhighercoldstrengthafterheattreatment,butlowerhotmodulusofrupture;(2)additionof5mass%andalusitecouldenhancethecoldandhotmodulusofrupture,improvethethermalshockresistance,andoptimizethemicrostructureofspecimens;(3)themullitizationofandalusitewasnotobviousinthecastablesfiredat1100-1400℃.
简介:UnipolarresistiveswitchingbehaviorsoftheZnOandAl2O3/ZnOfilmsfabricatedonflexiblesubstratesbypulselaserdepositionwerestudiedinthispaper.Thefilmsweredepositedatroomtemperaturewithoutpost-annealingtreatmentduringtheprocess.XraydiffractionresultsindicatedthatZnOfilmhasadominantpeakat(002).ScanningelectronmicroscopyobservationshowedacolumnargrainstructureoftheZnOfilmtothesubstrate.ThebilayerdeviceofAl2O3/ZnOfilmshadstableresistiveswitchingbehaviorswithagoodenduranceperformanceofmorethan200cycles,highresistiveswitchingratioofover103atareadvoltageof0.1V,whichisbetterthanthatofthesingleoxidelayerdeviceofZnOfilm.Apossibleresistiveswitchingfilamentarymodewasdemonstratedinthispaper.TheconductionmechanismsofhighandlowresistancestatescanbeexplainedbyspacechargelimitedconductionandOhmic’sbehaviors.Theenduranceofthebilayer(BL)devicewasnotdegradeduponbendingcycles,whichindicatesthepotentialoftheflexibleresistiveswitchingrandomaccessmemoryapplications.
简介:分析了影响45Mn17Al3钢磁导率性能的主要因素。通过工业试验确定了合理的化学成分、热处理工艺制度及试样表面加工要求等。试验结果表明,45Mn17Al3钢在800、4000及8000A/m三个磁场强度下,相对磁导率μr≤1.005,满足了某些特殊工程对磁性能的较高要求。
简介:One-potachievementofethyllevulinatefromcassavawasconductedinethanol-watersystemoverseveralsimplesulfatesaltcatalysts.Al2(SO4)3catalysthadthebestperformanceinsynthesizingethyllevulinatecomparingwiththoseofaseriesofsulfatesalts.Thehighestyieldsofethyllevulinatewasupto39.27%aswellas7.78%levulinateacidwhencassavawascatalyzedinethanolmediumbyadding10wt%water.13Cand1HNMRspectroscopicinvestigationsconfirmedthatisomerizationofglucosetofructoseoverAl2(SO4)3catalystisanimportantstepinproducingethyllevulinateandlevulinateacid.DuetoaggregationsofAl3+underhydrothermalconditions,tinyamountofAl3+weredetectedinfiltrateatthepercentageof0.32%evenifinabsolutewater.BronstedandLewisacidscouldimprovetheyieldofethyllevulinateandlevulinateacidbysynergisticeffect.AllresultssuggestedthatA12(SO4)3wasasimpleandefficientcatalystforethyllevulinateandlevulinateacidproduction.
简介:Inthepresentwork,anovelhybridcompositecomposedofTi-aluminidemulti-layeredpartandcontin-uous-SiCf-reinforcedTi-matrixpartusingavacuumhotpressing/hotisostaticpressure(VHP/HIP)sinteringprocesswassynthesized.Then,thedamagetolerancebehaviorofthishybridcompositewasstudiedbytensiletestsandinsituscanningelectronmicroscopy(SEM)three-pointbendingtests.Theresultsindicatethatthemechanicalpropertiesandcrackpropagationofthehybridcompositearestronglyinfluencedbytheextrinsictoughnessmecha-nism.Indetail,thecrackdeflectionofmulti-layeredcompositeandstrengtheningeffectofSiCf-reinforcedmatrixcompositeareobservedinthehybridcomposite.Owingtothestrengtheningeffectofcontinuous-SiCrre-inforcedTi-matrixpart,thetensilestrengthofhybridcompositeismuchhigherthanthatofneatTi-aluminidemulti-layeredcomposite.Furthermore,itisfoundthattheoptimaldamagetoleranceabilityisoptimizedwhenthenotchpositionislocatedattheTi-aluminidemulti-layeredpartduetothecrackdeflectionofmulti-layeredstructure.
简介:通过溶胶-凝胶法、离子束磁控溅射法和化学腐蚀法分别制备了PZT薄膜、PbZr_(0.52)Ti_(0.48)O_3/Ni(PZT/Ni)复合薄膜材料的鼓包样品。采用X射线衍射仪(X-raydiffraction,XRD)表征了PZT/Ni复合薄膜材料的物相结构;利用自主研制的多功能新型鼓包测试平台,在力场、电场、磁场作用下分别测试分析了PZT/Ni复合薄膜材料体系的力电磁耦合性能。结果表明:随着电场强度的增加,PZT薄膜的弹性模量E先增大后减小;PZT/Ni复合薄膜在电场作用下实现了电磁调控,矫顽磁场强度Hc提高了33.4%;随着测试平台油压的增大,PZT薄膜的剩余极化强度和矫顽场分别增加了17.1%和32.1%,PZT/Ni复合薄膜的矫顽磁场强度提高了46.1%。
简介:目的:探讨血清抵抗素水平与FT_3的相关性。方法:抽取本院149例门诊患者血清标本,根据血清游离三碘甲状腺原氨酸(FT_3)含量的不同,分为高FT_3组、低FT_3组和NC组,分别检测FT_3、抵抗素、空腹血糖、空腹胰岛素及甘油三酯水平,分析抵抗素与各项指标之间的关系。结果:三组在空腹胰岛素(FIns)、空腹血糖(FBG)及甘油三酯(TGA)方面比较无显著性差异,P〉0.05;FT_3含量比较,高FT_3组最高,低FT_3组最低,P〈0.05,差异具有统计学意义;抵抗素比较,NC组与低FT_3组比较无显著性差异,P〉0.05,但两组抵抗素指标均明显低于高FT_3组,P〈0.05,差异具有统计学意义。结论:血清抵抗素水平与FT_3呈正相关性。