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1、AbstractAbstractCalciastabilizedzirconia(CSZ)ceramicshavebeenwidelyusedinoxygensensors,oxygenpumpsandhightemperatureheatgeneratorduetotheirrelativelyhighionicconductivity,lowheatconductivity,hightemperaturechemicalstability,andoutstandingthermalshockresistance.Inthiswork,usingzirconiaan
2、dcalciumnitrateasrawmaterials,aseriesofCSZceramicswerepreparedviapressurelesssinteringmethod,andtestedtherelativedensitiesandopenporosityofthesinteredsamples.TheparticlesizeofCSZpowderwasanalyzed.PhasetransformationwascharacterizedbyXRDandRamanspectroscopy;microstructurewasrepresentedby
3、SEM;electricalpropertywastestedbyACimpedancetechnology.Inaddition,theeffectofCaOadditiveamount,sinteringtemperature,phases,andmicrostructureontheelectricalpropertiesarediscussedemphatically.Theresultsareasfollowing.Thesinteredsampleshavehighrelativedensity.WiththeincreaseofCaOadditiveam
4、ount,therelativedensityfirstlyincreaseandthendecrease.Elevatingthesinteringtemperature,theopenporositydeclines.ThemainphasesofsinteredsamplesiscubicZrO2(c-ZrO2)andtetragonalZrO2(t-ZrO2).Asmallamountofmonocliniczirconia(m-ZrO2)ispresentinafewofsamples.Byincreasingeitherthesinteringtemper
5、atureorCaOadditiveamount,thephasesgraduallyturnfromc-ZrO2,t-ZrO2andm-ZrO2intoc-ZrO2andt-ZrO2,finallyonlyc-ZrO2left.GrainboundarywasclearinthesectionofCSZceramics,andgrainsizeisrelativelyuniform.ThemainfracturemodeofCSZceramicsisintergranularfracture.TheionicconductivityofCSZceramicsisde
6、terminedbytheconcentrationandmobilityofoxygenvacancies.VaryingtheCaOadditiveamount,the5.0wt%sinteredsamplesisfoundtoownthehighestionicconductivity,inwhichtheconcentrationofoxygenvacanciesstayatanappropriatelevel.Thesinteringtemperaturealsoaffectstheconductivityviachangingthephasesandgra
7、in.TheconductivityisrelatedtothephaseratiosofCSZceramics;andtheratiosofc-ZrO2andt-ZrO2shouldrangeinanappropriateregion.Smallanduniformgrain,aswellaslargerquantitiesofgrainIII万方数据硕士学位论文boundary,contributetooxygenvacancytransferandbetterconductivityofCSZceramicsasaresult.Ascalcul