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1、摘要纳米ZrO2马氏体相变有关问题的研究摘要本文系统总结了现有的t-ZrO2纳米晶在低温下稳定存在的各种机制，并对其相关问题进行了试验与分析。（1）在不添加任何分散剂以及表面剂的条件下，运用沉淀法制备出纳米级ZrO2粉体。（2）随着球磨时间的增长，t相氧化锆的含量降低，m相氧化锆的含量增加，发生了t相向m相的转变。由于晶粒的大小没有发生改变，晶粒内的氧含量也没有发生改变，球磨引入了大量的缺陷，有利于马氏体相变的形核，从而促进了t相到m相的转变。（3）经过淬火处理后的Ce,Y-TZP不但出现驰豫内耗峰，还出现了相变内耗峰。Ce,Y-TZP陶瓷
2、的机械驰豫和介电驰豫均来自于Yzr’VÖ偶极子的再取向。（4）纳米氧化锆颗粒的镍基复合镀层，通过不同的制备方案和不断的工艺改造，试图探索最佳的制备方法。关键词：ZrO2，电镀，球磨，内耗AbstractSTUDYOFMECHANISMSOFROOMTEMPERATUREMETASTABLETETRAGONALPHASESTABILISATIONINZIRCONIAABSTRACTPreparationofnanocrystallineZrO2,co-electrodepositionofnanoZrO2whiskersnickelcompo
3、sitecoating,ballmillingofZrO2andinternalfrictionofCe,Y-TZPareinvestigated.Somenewresultsarepresented.（1）Thefabricatingconditionsandprocessingofnanometerzirconiaceramicspowdersareintroduced.MicrostructureofnanozirconiapowdersischaracterizedbyusingTransmissionElectronMicrosc
4、ope(TEM)andX-RayDiffraction(XRD).（2）t-ZrO2m-ZrO2occurredbyballmilling.Thereasonisthatcrystaldefectswereintroducedbyballmilling,whichgoesagainstofthestabilizationoft-ZrO2.（3）Theroomtemperature(RT)-250℃internalfriction(IF)forquenched8Ce,0.5Y-TZPceramicsandRT-400℃dielectriclo
5、ss(DL)for8Ce,0.5Y-TZPand8Ce,0.75Y-TZPceramicswerestudied.Alongwitharelaxationpeak,whichistypicalofnormal8Ce,0.5Y-TZP,twoprominentIFpeaksassociatedwithphasetransformationwereobservedinIFspectraforquenched8Ce,0.5Y-TZP.Theactivationenergyisdiscoveredtobeidenticalforboththemec
6、hanicalanddielectricrelaxation.Moreevidencesarefoundthatreorientationof上海交通大学硕士学位论文Yzr’VÖanisotropiccomplexesformedbyoxygenvacanciesandsubstitutionalyttriumionswereconfirmedtobetheoriginoftherelaxationpeakofCe,Y-TZPceramics.（4）Thepreparationofnano-ZrO2inNickelplatinghasbee
7、nextensivelystudied.Theexperimentresultshaveshownthatthepropertiesofthecompositecoatingsaregreatlyaffectedbymanytechnologicalparameterssuchasthesurfaceconditionsofthehostmetals,thepositionsofnegativeandpositivepoles,pHvalueoftheelectrolyte,etc.KEYWORDS:ZrO2,compositecoatin
8、g,ballmilling,internalfriction上海交通大学学位论文原创性声明本人郑重声明：所呈交的学位论文，是本人在导师的指导下，独立进行研究工作所取得的成果。除文
