简介:TheinfluenceofrareearthoxideCeO2onmicrostructureandwearresistanceofM80S20thermalsprayandthermalsprayweldingcoatingsisstudiedusingopticalmicroscope,scanningelectronmicroscope,X-rayenergydispersionspectroscope,X-raydiffractometerandweartestingmachine.Theresultsshowthattheaddi-tionof8%CeO2canimprovethemicrostructure,microhardnessandwearresistanceofcoatingssignificantly.
简介:采用Gleeble热模拟试验机研究了不同轧制应变速率、不同终轧温度、不同轧后冷速对20CrMnTiH齿轮钢带状组织的影响。研究结果表明,轧制应变速率0.05s-1、终轧温度940℃、轧后冷却速度0.8℃/s时,试验试样的铁素体带宽最窄。通过工业化试验,以Gleeble热模拟试验结果为指导并结合本钢特钢生产过程实际情况,使20CrMnTiH齿轮钢的带状组织级别控制在2.0级以下,达到了很好的效果。
简介:InordertoimprovethehydrogenationanddehydrogenationperformancesoftheMg2Ni-typealloys,MgwaspartiallysubstitutedbyLainthealloy,andmeltspinningtechnologywasusedforthepreparationoftheMg20-xLaxNi10(x=0,2,4,6)hydrogenstoragealloys.ThestructuresofthealloyswerestudiedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andhigh-resolutiontransmissionelectronmicroscopy(HRTEM).Itwasfoundthatnoamorphousphaseformedintheas-spunLa-freealloy,buttheas-spunalloyscontainingLaheldamajoramorphousphase.WhenLacontentx≤2,themajorphaseintheas-castalloyswasMg2Niphase,butwithfurtherincreaseofLacontent,themajorphaseoftheas-castalloyschangedintoLaNi5+LaMg3phase.Thermalstabilityoftheas-spunalloyswasstudiedbydifferentialscanningcalorimetry(DSC),showingthatspinningratewasanegligiblefactoronthecrystallizationtemperatureoftheamorphousphase.Thehydrogenabsorptionanddesorptionkineticsoftheas-castandas-spunalloysweremeasuredusinganautomaticallycontrolledSievertsapparatus,confirmingthatthehydrogenabsorptionanddesorptioncapacitiesandkineticsoftheas-castalloysclearlyincreasedwithrisingLacontent.ForLacontentx=2,theas-spunalloydisplayedoptimalhydrogendesorptionkineticsat200°C.
简介:TheNd60Fe20Al8Co10B2alloywaspreparedbysuctioncastingofthemoltenalloyintoacoppermoldunderargonatmosphere.Themicro-structuralandmagneticpropertychangesintheNd60Fe20Al8Co10B2alloyduringcrystallizationwereinvestigatedbyX-raydiffraction(XRD),differentialscanningcalorimetry(DSC),scanningelectronmicroscope(SEM)andthevibratingsamplemagnetometer(VSM).TheprecipitationandNd-richandFe-richphaseshavenosignificanteffectontheintrinsiccoercitityforNd60Fe20Al8Co10B2alloyannealedbelow723K.However,thegrowthofFe-richphasedecreasesthesaturatemagnetizationandremanenceofthealloy.Thehardmagneticbehaviorisdisappearedwhenthealloyisfullycrystallized.