dd5单晶合金的定向凝固组织与模壳热导体的应用分析

《dd5单晶合金的定向凝固组织与模壳热导体的应用分析》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、万方数据DD5单晶合金的定向凝固组织及模壳热导体的应用研究StudiesonMicrostructuresofDirectionallySolidifiedSC-AlloyDD5andApplicationsofHeatConductorinMoldShells姓2015年4月万方数据江苏大学硕士论文ABSTRACTNickel—basedsuperalloyhavebeenwidelyusedinthefieldofaircraftenginesandgasturbinesduetoitsgoodheatresistan

2、ce，oxidationresistance，corrosionresistanceandthermalcreepresistance．Itisagreatsignificancetomakeresearchesonthepreparationprocessandcastmicrostructureofsinglecrystalblades．Thispaperchoosesdomesticsecondgenerationnickel—basedsinglecrystalsuperalloyDD5asresearchobje

3、ct．TwokindsoftestbarsaremadebyHRSmethodwhichwith3mm／minwithdrawalrate．UseX—mystodoqualitativeanalysisofthephasethattestbarscontain；useDTAmethodtomeasureit’Stransformationtemperature．solidusandliquidustemperature．Measuretheprimarydendriteandseconddendriteannspacing

4、，furtherstudythesizeandmorphologyofthe丫，丫’．Meanwhile，segregationdegreeofalloyelementsfordifferentheightsfromcopperchillwereanalyzedbytheEnergyDispersiveSpectrometer．Furthermore，theapplicationofHeatconductorinmoldshellsWasstudied．Alloftheworkwedoistopavethewayforth

5、epreparationofthesinglecrystalbladeswitllcomplexshape．Mainconclusionsinthispaperasfollows：ThesolidustemperatureofDD5superallyis1295℃，andtheliquidustemperatureis1386。C．Thesuperalloy’ScaststructureshowatypicaldendritemorphologyandasmallamountofeutecticstructureWaslo

6、catedintheinterdendritic．Thesizeofthe丫7phaseinthedendriteissmallerthanthatintheinterdendritic，andhavethemoreuniformmorphology,theshapeof7’phaseinthedendriteincreasingly仃endstocubeanditalwaysoccurinpairs．Butthemorphologyandsizeof丫’phaseintheinterdendriticisirregula

7、r,itoftenOCCurIngroups．Thespacingofprimarydendriteisincreasingwiththedistanceincreasesfromwater-cooledcopperplate，howeverthespacingofsecondarydendritearl／1islittledifferenceandcompared、)~ritllthetestbarsofsinglecrystal．thedendritearlTlspacingissmallerthanthetestba

8、rsofcolumnargrainunderthesameheight．Aboutthetestbarsofcolumnargrain．wefindseconddendritearminstabilityandthetllirddendritearrnalsoappearatthecrosssectio