高温合金叶片铸造用氧化铝陶瓷型芯充型性能的研究

高温合金叶片铸造用氧化铝陶瓷型芯充型性能的研究STUDYONFILLINGPERFORMANCEOFALUMINABASEDCERAMICCORESFORINVESTMENTCASTINGSUPERALLOYBLADES杨冬野2007年6月图书分类号：TG249.5U.D.C.:621.74工学硕士学位论文高温合金叶片铸造用氧化铝陶瓷型芯充型性能的研究硕士研究生：杨冬野导师：田竞副教授申请学位：工学硕士学科、专业：材料加工工程所在单位：材料科学与工程学院答辩日期：2007年7月授予学位单位：哈尔滨工业大学ClassifiedIndex:TG249.5U.D.C.:621.74DissertationfortheMasterDegreeinEngineeringSTUDYONFILLINGPERFORMANCEOFALUMINABASEDCERAMICCORESFORINVESTMENTCASTINGSUPERALLOYBLADESCandidate：YangDongyeSupervisor：Ass.Prof.TianJingAcademicDegreeAppliedfor：MasterofEngineeringSpecialty：MaterialsProcessingEngineeringAffiliation：SchoolofMaterialsScienceandEngineeringDateofDefence：July,2007Degree-Conferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学工学硕士学位论文摘要用于生产高温合金叶片的氧化铝陶瓷型芯化学稳定、抗蠕变性能好，可保证内腔结构复杂的定向柱晶和单晶空心叶片的尺寸精度和合格率，并能降低叶片的制造成本，但是在实际生产中氧化铝陶瓷型芯浆料充型存在很大问题，限制了氧化铝陶瓷型芯的应用。本文对氧化铝陶瓷型芯浆料流变性能的研究，发现氧化铝陶瓷型芯的浆料有一定的沉降过程，并具有触变性，浆料粘度随温度的变化主要是由浆料中石蜡的流动性决定的，在较高温度时，浆料的粘度变化不大，但当温度下降时，浆料的粘度大幅度上升；氧化铝陶瓷浆料在低剪切速率下，型芯浆料呈剪薄型，而在高剪切速率下，型芯浆料呈剪厚型。为了研究不同因素对浆料充型性能的影响，设计评测氧化铝陶瓷型芯浆料的模具，通过流变性的研究，选择合适的浆料温度、模具温度及充型压力参数，进行正交实验，结果表明充型压力是浆料充型时最大的影响因素，模具温度的影响最小。对陶瓷型芯粉体的颗粒进行了粒度分析，颗粒由不同大小的颗粒组成，烧结后型芯中的大颗粒形成高温骨架，细颗粒填充在粗颗粒的空隙中，加固高温骨架，具有很好的烧结强度，烧结之后具有较高的孔隙率，有利于脱芯。陶瓷型芯在高温时的热膨胀率及热膨胀系数都很小，型芯有很好的高温尺寸稳定性。氧化铝相和二氧化硅相变化很小。关键词氧化铝陶瓷型芯；流变性；充型性能；正交实验--I哈尔滨工业大学工学硕士学位论文AbstractAluminabasedceramiccores,usedforproducingbladesofsuperalloy,areofgoodchemicalstabilityandcreepresistance.Theycanguaranteethedimensionalprecisionandqualifiedrateofdirectionalsolidificationhollowbladesandsinglecrystalhollowblades,whichhavecomplexborestructures,anddecreasethemanufacturingcost.Butinactualproductiontherearemanyproblemsinthediefillingprocess,whichrestricttheapplicationofaluminabasedceramiccores.Inthispaper,therheologicalpropertyofaluminabasedceramiccoresslurryhasbeensystematicallyinvestigated.Itisfoundthattheslurryhasasettlementprocessandthixotropicproperty.Theviscosityofslurryischangedwithtemperature,andthesechangesarerelatedwiththeliquidityofparaffinwax.Inthehighertemperature,thechangesoftheviscosityarenotobvious;inthelowertemperature,theviscosityincreasessharply.Inthelowrateofshear,alongwiththeincreaseofrate,theviscosityofslurryreduces;inthehighrate,theresultiscontrary.Inordertoresearchthedifferentfactorsaffectingtheperformanceofdiefillingofthefusiblepattern,themoldforevaluatingtheslurryofaluminabasedceramiccoresiswelldesigned.Afterselectingthesuitableslurrytemperature,moldtemperatureanddiefillingpressure,theorthogonalexperimentshavebeencarriedon.Theresultsshowthatthepressureisthebiggestinfluencingfactorinthefillingofslurryandthemoldtemperatureistheleast.Theanalysisofceramiccoresgrainsindicatesthatthegranulesarecomposedofdifferentsizeparticles.Thebiggerparticlesformhightemperatureframeworkaftersintering,andfineparticlesfilltheinterspacesbetweenthecoarsegranulestoreinforcetheframework,whichmaketheceramiccorehaveagoodsinteringstrength.Ithasahigherrateofporosity,whichisgoodforleaching.Inthehightemperaturethethermalexpansionandthermalexpansivityofceramiccoresaresmall,andthesizestabilityisextremelygood.Thechangesofaluminaandsilicaphaseareverylittle.--II哈尔滨工业大学工学硕士学位论文KeywordsAluminabasedceramiccore,Rheologicalproperty,Diefillingofthefusiblepattern,Orthogonalexperiment--III哈尔滨工业大学硕士学位论文目录摘要......................................................................................................................IAbstract................................................................................................................II第1章绪论.........................................................................................................11.1引言............................................................................................................11.2陶瓷型芯发展及应用................................................................................21.2.1氧化硅系列陶瓷型芯.........................................................................21.2.2氧化铝系列陶瓷型芯.........................................................................31.3氧化铝型芯的研究现状............................................................................81.3.1料浆稳定性理论.................................................................................81.3.2固相含量对料浆流变性的影响........................................................101.3.3分散剂对浆料流变性的影响............................................................101.4本文主要研究内容..................................................................................11第2章实验材料及型芯充型性能的测试方法................................................132.1实验材料成分..........................................................................................132.1.1陶瓷型芯基体材料的选择...............................................................132.1.2陶瓷型芯矿化剂的选择...................................................................132.1.3陶瓷型芯增塑剂的选择...................................................................142.2实验过程及测试方法..............................................................................152.2.1陶瓷型芯浆料流变性能的研究........................................................152.2.2陶瓷型芯浆料充型性能的研究.......................