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500 个结果
  • 简介:ThemixturemodelofAl85Y4Nd4Ni7alloyinwhichapartiallycrystallizedamorphousalloyisregardedasananocompositeofanAlnanoparticleandaremainingamorphousmatrixispresented.Itsevolutionintheprocessofcrystallizationhasbeeninvestigatedbydifferentialscanningcalorimetry(DSC),X-raydiffraction(XRD),andtransmissionelectronmicroscopy(TEM).Mainlyamorphousstructurewithα-Alnanocrystalsembeddedintheamorphousmatrixhasbeenrevealedbymeltspiningthealloy.Crystallizationisshowedtooccurinthreestages:(1)crystallizationofamorphousalloyandformationofAlNiY,AlNdNiandunknowncrystallinephases,(2)formationofAl3YandAl3Nd,and(3)formationofAl3Ni.

  • 标签: 无定形合金 Al85Y4Nd4Ni7合金 结晶化行为 微观结构
  • 简介:Abstract:TheeffectofTiandNbontherecrystallizationandtherecrystallizedgrainsizeofthehot-rolledplatesandcold-rolledsheetsofultralowcarbonandnitrogen(ULCN)Cr18ferriticstainlesssteel(FSS)isinvestigated.Theresultsshowthattherecrystallizationofhot-rolledplatesandcold-rolledsheetswith0.29%Nbisdelayed,andtherecrystallizedgrainsaresignificantlyrefined.

  • 标签: 不锈钢冷轧薄板 再结晶 超低碳 晶粒尺寸
  • 简介:Si3N4powderandhot-pressedSi3N4ceramicsaddedwithAl2O3areusedforinvestigatetheiroxidationbehviorinairandnitrogenatmosphere(withoxygenpartialpressurePO2=1-10Pa),TheoxidationproductsofSi3N4areexaminedbychemicalanalysi,X-raydiffraction(XRD)andXPSmethod,Also,thermodynamiccalculationismadetoanalyzeoxidationbehaviorofSi3N4.TheresultsshowthatonlypassiveoxidationwilloccurwhenSi3N4isoxidizedinairathightemperature,whereasinN2athightemperature,theactiveoxidationisdominantinspiteoftheexistenceofalittlepassiveoxidation.

  • 标签: 氧化反应 四氮化三硅 陶瓷工业 制陶术 空气 氮气
  • 简介:ThemechanicalpropertiesofpressurelesssinteringFe-Si3N4bondedSiCandSi3N4bondedSiCwithsamemanufactureprocesshavebeencomparedinthispaper.TheoxidizingmechanismofFe-Si3N4bondedSiCceramicmatrixcompositehasbeeninvestigatedespeciallythroughTG-DSC(thermogravimetricanalysis-differentialscanningcalorimeter)experiment.DuringoxidationprocedurethemainreactionistheoxidationofSiCandSi3N4,SiO2whichformprotectingfilmtopreventfurtheroxidizing.AndresidualironinthesamplesbecomeFe2O3andFe3O4,theoxidationkineticsat1100~1300℃ofre-Si3N4bondedSiChasbeenstudiedespecially.Theweightgainperunitareaatinitialstagechangesaccordingtobeelinerule,inthemiddleaccordingtoconic,andinthelastoxidationperiodfollowsparabolarule.

  • 标签: SIC SI3N4 耐火材料 热冲击 等温线
  • 简介:Usingtransganglionicdegenerativemethed,weinvestigatedtheprimaryafferentinformationofacupointsofQuanliao(SI18)andShibai(ST2).Theresultsshowedthatthelargeamountsofdegenerativefiberscouldbefoundbilaterallyintrigeminalspinalnucleusanditstract,trigeminalprincipalsensorynucleus,trigeminalmesencephalicnucleusandsomedegenerationscouldbeobservedipsilaterallyinsolitarytractanditsnucleus,medullarylateralreticularnucleus,giganto-cellularreticularnucleusandnucleusraphemagnusfollowingtransectionofinfraorbitalnerve.Averymoderatedegenerativefiberscouldbeidentifedinipsilateralaccessoryspinalnucleusandspinalreticu-larnucleus.Afewdegenerativefiberswereseenonthecontralateralmagnocellularpartofcaudatepartoftrigeminalspinalnucleusbypassingthroughtheposteriorcommissureofcanaliscentralis.TheseresultssuggestthattheprimaryinformationofacupointsofQuanliaoandShibaicouldbetrans-mitteredintotheabovestruc

  • 标签: Transganglionic DEGENERATION Infraorbital NERVE ACUPOINT AFFERENT
  • 简介:Improvingtheunitheatefficiency,reducingcoalconsumptionandtheemissionofCO2andmeetingtherequirementsofenvironmentalprotectionandenergyconservationisthegoaloftheboilerandthepowerindustry.Developmentsoflargecapacityandhighparameterultra-supercritical(USC)unitsarethetendencyofthepowerindustry.ThereisnodoubtthatthedevelopmentofUSCunitsisbasedonthedevelopmentofmaterials,especiallythematerialsusedforsuper-heaterandreheaterinhigh-temperatureUSCboiler.Duetothelongtimeexposuretotheharshenvironment,suchasbearingthe600℃steamoxidation,andwithstandingthecorrosivefluegasandflyasherosion,thematerialsrequirenotonlygoodhigh-temperaturestrength,butalsoagoodcorrosionresistance.Inconsiderationoftherequirementscitedabove,foreigncountrieshaddevelopedTP310HCbN(07Cr25Ni21CbN)austeniticheat-resistantsteel.However,thedomesticdemandsforthismaterialstilldependonimportandthecostishigh,sotheboilerandthepowerindustryexpectseagerlythatthesesteelscanbeproducedbydomesticmetallurgicalindustry,especiallyBaosteel,toreplacetheimportedproducts.Inordertosatisfytherequirementsofdomesticmanufacturingsuper-heaterandreheaterusedinultra-supercriticalpowerboiler,afterdevelopedT23、T91、T92、S30432highpressureboilertube,BaosteelbegantodevelopTP310HCbN(07Cr25Ni21CbN)austeniticstainlesssteeltubeinJanuaryof2007.Thisstudydescribesthecompositiondesign,themanufacturingprocessofproduct,andtheassessmentofperformanceofBaosteel’sTP310HCbN(07Cr25Ni21CbN).ThedataindicatesthatpropertiesofBaosteel’sTP310HCbN(07Cr25Ni21CbN)conformtotheASMESA-213standardandGB5310standard,soitcansubstitutetheimportedproductsandissuitableformanufacturingpowerstationboilerofgreatcapacityandhighsteamparameters.

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  • 简介:研究设计了三种不同成分Cr25Ni30耐热合金,并对其组织特征及常温和高温性能进行了测定。结果表明:w(Al)为5%的合金室温拉伸强度最高,金属组织中出现较多的Ni-Al金属间化合物,显著降低其塑性;w(Al)为3%的合金塑性最好,但强度较低;w(Nb)为2%的合金抗氧化性最好,高温强度最高,综合性能最好。

  • 标签: 耐热合金 热强性 抗氧化性
  • 简介:Thisstudyinvestigatesthecorrosionpropertiesof0Cr11Tiand0Cr11NbTiferriticstainlesssteels(FSS)forautomotiveexhaustsystems.Theresultsindicatethatthebasemetalandweldseamof0Cr11NbTisteelexhibitbetterintergranularandcondensatecorrosionresistantpropertiesbecausecarbonandnitrogenarestabilizedbyNbandTi,andtheprecipitationofCrcarbideisretardedingrainboundaries.

  • 标签: 铁素体不锈钢 汽车排气系统 防腐性能 碳化物析出 晶间腐蚀 FSS
  • 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:DenseSi3N4BNcompositeceramicswerefabricatedbysparkplasmasinteringat1500,1600and1650℃under50MPafor5minusingSi3N4andBNpowdersasstartingmaterialsand2mass%Al2O3and6mass%Y2O3assinteringadditives.ThevolumefractionofBNinSi3N4BNcompositepowderswaschosenas10%,20%,and30%,respectively.TheresultsofXRDandSEMshowthatα-Si3N4completelyturnsintoβ-Si3N4whenthecompositeceramicsaresinteredat1650℃;theadditionofBNhindersthegrowthofSi3N4grains,refiningthestructure;VickershardnessandfracturetoughnessofthecompositeceramicsdecreasewiththeincreaseofBNcontent.

  • 标签: 放电等离子烧结 复合陶瓷材料 氮化硅 物业 Al2O3 X射线衍射
  • 简介:Themechanicalproperties,creepdamage,creeprupturestrengthandfeaturesofinterfacialfailuresofweldedjointsbetweenmartensite(SA213T91)andpearlitesteel(12Cr1MoV)havebeeninvestigatedbymeansofargontungstenpulsedarcwelding,hightemperatureacceleratedsimulation,creeprupture,mechanicalpropertytestsandscanningelectronicmicroscope(SEM).Theresearchresultsindicatethatthemechanicalpropertiesofovermatchedandmediummatchedjointdeteriorateobviously,andtheyaresusceptibletocreepdamageandfailureafteracceleratedsimulationoperation500h,intheconditionofpreheat250℃,andpostweldingheattreatment750℃×1h.However,themechanicalpropertiesofundermatchedjointarethebest,theinterfacialfailuretendencyofundermatchedweldedjointislessthanthoseofmediumandovermatchedweldedjoint.Therefore,itisreasonablethatlowalloymaterialTR31isusedasthefillermetalofweldbetweenSA213T91and12Cr1MoVsteel.

  • 标签: 10Cr9Mo1 12CR1MOV 焊接接头 机械性能 结构钢 SEM
  • 简介:HighlytexturedHeusleralloyMn46Ni42Sn11Sb1ribbonswerepreparedbymeltspinning.TheannealedhighMncontentMn46Ni42Sn11Sb1ribboncross-sectionmicrostructure,crystalstructure,martensitictransformation(MT),andmagnetoresistance(MR)propertieswereinvestigated.TheMRintheannealedribbonwasassessedbythemagneticfielddirectionperpendiculartotheribbonsurfacewiththemagneticfieldupto30kOe.Thelargenegativevalueof25%forMRwasobtainedat244K.Theexchangebias(EB)effectsoftheas-spunandannealedribbonswereinvestigated.Afterannealing,theEBeffectshavebeenimprovedbyabout25Oeatthetemperatureof50K.Themagnetizationshaveincreasedapproximatelyby10%morethantheas-spunribbon.

  • 标签: 锰含量 磁电阻 合金带 交流 熔融纺丝工艺 磁场方向
  • 简介:(Ni0.81Fe0.19)0.66Cr0.34hasahighresistivityandacrystalstructureclosetothatofNi0.81Fe0.19.TheelectricalandX-raydiffractionmeasurementsprovethatathinNiFeCrseedlayerinducesawell(111)-orientedNi0.81Fe0.19film.Post-annealingtreatmentimprovesthemagneticpropertiesof(Ni0.81Fe0.19)0.66Cr0.34(45A)/Ni0.81Fe0.19(150A)/Ta(55A)thinfilmpreparedunderadepositionfield,whereastheinter-diffu-sionofNiFe/Tadeterioratesthemagnetoresistancepropertiesofthefilm.

  • 标签: 微观结构 AMR 各向异性磁致电阻效应 坡莫合金膜 (Ni0.81Fe0.19)0.66Cr0.34缓冲器
  • 简介:采用环境氢脆技术及现代材料微观分析技术,研究了Fe-35Ni-15Cr实验合金在室温至900℃的力学性能及热充氢后在室温及750℃的力学性能,分析了温度对材料微观组织的影响,为优化其化学成分、热处理工艺等提供技术依据。

  • 标签: 力学性能 微观组织 合金 温度 现代材料 热处理工艺
  • 简介:为了对高合金异种钢焊接工艺有更多的了解,本文通过对某火力电厂锅炉后屏过热器检修换管过程中涉及到的钢种(SA213-T91马氏体高合金耐热钢与Cr25Ni13奥氏体高合金耐热钢)的现场焊接工艺进行介绍,以给类似工程的施工提供一定的借鉴。

  • 标签: SA213-T91钢 Cr25Ni13钢 焊接工艺 异种钢焊接 活动夹块
  • 简介:某型号飞机电缆装配前进行例行检查时,发现ZG0Cr14Ni5Mo2Cu上位锁支臂开裂。通过现场调查、对断裂件的材料成分分析、金相组织观察、断口的宏微观观察、硬度检测以及设计结构、受力及现行工艺等综合分析,以确定该上位锁支臂断裂的性质及产生原因。结果表明:上位锁支臂的断裂为过大的装配应力、校形残余应力与氢共同作用下的氢致脆断造成的。此案例分析中发现了隔板设计结构、校形的残余应力问题,为此提出了合理的改进建议。

  • 标签: 上位锁支臂 装配应力 残余应力 氢致开裂