简介:AseriesofDy(Gd)-basedbulkamorphousalloyrodswerepreparedbywater-cooledcoppermoldmethod.ThermalstabilityandstructureofDy-Gd-Co-AlalloyswereinvestigatedbydifferentialscanningcalorimetryandX-raydi-raction,respectively.TheresultsshowthattheDy-Gd-Co-Alalloyshavegoodglass-formationability,andtheDy31Gd25Co20Al24alloycanbereadilycastintofullglassyrodsupto5mmindiameter.Theglass-formingabilityofmulticomponentalloyswasgreatlydependentontheirchemicalinteractionandtheequivalentbondparametersamongatomssuchasequivalentelectronegativitydierence,equivalentatomicsizeparameter.TheDy(Gd)-basedbulkamorphousalloyscouldbeexpectedaspotentialfunctionalmaterials.
简介:Basedontheclassicdiffusioncontrollednucleationandgrowththeory,thesympatheticnucleationledgewisegrowthmechanismofbainitewasstudiedtheoreticallyforIowcarbonFe-Calloys.Therationalityoftheoccurrenceofsympatheticnucleationontheterracesofledgescompetingwithlateralledgegrowthandothersitesnucleationwasdemonstratedbythepresentworkquantitatively.ThecalculationsindicatedthatIowreactiontemperaturesandhighcarbonconcentrationsmayfavorthesympatheticnucleation,thusaccountingfortheformationofmultilayerstructuresofbainite.
简介:为stoichiometric作文的nanocrystallineNd-Fe-B磁铁的demangetization曲线被使用微磁力的有限元素技术计算。曲线,特别iHc随N.The很小的iHc的增加变得更小从一系列沿着不同的地方向的曲线为N=∞接近那。iHc随L的增加增加,并且是什么的靠近的cr一些比小试验性的价值应该是。
简介:论述了CA-FE(元胞自动机-有限元)法模拟金属材料凝固微观组织的原理及国内外的研究现状,提出了目前存在的问题和进一步的研究趋势,特别是应用到有色金属材料和贵金属材料的凝固微观组织的计算机模拟研究中。
简介:Manganesephthalocyanine(MnPc)-Fe3O4nanoparticlescompositewaspreparedandcharacterized.TheresultsshowthatMnPcarecompletedonthesurfaceofFe3O4nanoparticlesinthestateofsinglemolecule.ThereiseffectivecompositebetweenMnPcandFe3O4nanoparticleswhichcanimprovetheantioxidizationabilityofFe3O4nanoparticlesgreatly.Thecompositewasdispersedintochlorinatedparaffinoiltoformelectromag-netorheological(EMR)fluidwithhighactivity,andtheEMRpropertiesofthisEMRfluidarestudied.
简介:以硬脂酸锌为Zn源、硫化钠为S源,首次采用油水界面法制备出单分散于环己烷和甲苯的ZnS纳米材料,探索有机溶剂、锌源和油酸浓度等对紫外吸收影响的同时,以ZnS为基质,掺杂Mn^2+和Eu^3+制得ZnS:Mn^2+,Eu^3+发光纳米材料,采用高分辨率透射电子显微镜(HRTEM)、X射线粉末衍射仪(XRD)、紫外可见(UV-VIS)和荧光分光光度计(PL)对产物进行了表征,紫外和HRTEM测试结果均表明,产物为单分散性,平均粒径为4.3nn;荧光测试表明,产物所发荧光较强,肉眼可观测到明显的橙黄色(585nm)和橙红色(616nm)发光;XRD结果显示,产物结构为立方闪锌矿结构
简介:从同样渗出的镁合金Mg-3%Al-1%Zn(AZ31)营舍准备的样品在低周期的疲劳测试被利用以便调查频率依赖者疲劳生活。充分颠倒的控制紧张的紧张压缩疲劳测试在空中在1Hz和10Hz的频率被执行。微观结构被光显微镜学(OM)和扫描电子显微镜学(SEM)检验。当紧张振幅比0.2%低时,疲劳生活与装载频率展出了积极关联,并且twinning的活动在10Hz被增加。当紧张振幅比0.2%高时,重要twinning在生活被发现独立于频率的这二频率,和疲劳被观察。为这频率相关的疲劳一生的可能的原因可能由于在装载频率和紧张振幅之上的twinning的依赖。
简介:Theliquidphasebehaviorofthefine-grained5083Alalloyobtainedthroughthermomechanicalprocesswasinvestigatedduringthetensiletestsinatemperaturerangeof380-570-Candstrainraterangeof4.17×10-4-1.0×10-2s-1.Themaximumelongation530%ofthefine-grained5083Alalloywasobtainedat550-Cand4.17×10-4s-1.Fractureanalysisbyscanningelectronmicroscopy(SEM)indicatedthattheformationoffilament(formedbyliquidphase)wasgreatlyaffectedbythetensiletemperatureandstrainrate.Theresultsalsoshowedthattheoptimummorphologyofformedfilamentwasobtainedat550-Candastrainrateof4.17×10-4s-1.Theeffectofliquidphaseonsuperplasticdeformationofthealloywasfurtherdiscussed.