2023年全國(guó)碩士研究生考試考研英語(yǔ)一試題真題（含答案詳解+作文范文）_第1頁(yè)
已閱讀1頁(yè)，還剩90頁(yè)未讀， 繼續(xù)免費(fèi)閱讀

下載本文檔

版權(quán)說(shuō)明：本文檔由用戶(hù)提供并上傳，收益歸屬內(nèi)容提供方，若內(nèi)容存在侵權(quán)，請(qǐng)進(jìn)行舉報(bào)或認(rèn)領(lǐng)

文檔簡(jiǎn)介

1、東南大學(xué)碩士學(xué)位論文MgGd系高強(qiáng)變形鎂合金的研究姓名：吳旻申請(qǐng)學(xué)位級(jí)別：碩士專(zhuān)業(yè)：材料學(xué)指導(dǎo)教師：薛烽20090901摘要InvestigationonHigh—performanceWroughtMgGdAlloysABSTRACTWroughtMg—REalloyshaveattractedincreasinginterestinrecentyearsduetotheirexcellentcreepresistance，corro

2、sionresistanceandmechanicalpropertiesInthepresentwork，micro—structuresandmechanicalpropertiesofMgGdbinaryalloysandMgGdNd(GN)ternaryalloyshavebeeninvestigatedsystematicallybyoptical(OM)，scanningelectronmicroscope(SEM)，Xra

3、ydiffractmeter(XRD)，inductivelycoupledplasma(ICP)andtransmittingelectronmicroscope(TEM)eteThemicrostructuresofaseastMg—Gdbinaryalloysconsistedofthe僅MgmatrixanddispersivelydistributedMgsGdparticlesWiththeincreaseofGdaddit

4、ionthevolumefractionofthesecondphaseincreasedwhilethedimensionofthematrixgrainsreducedtosomeextent11圮microstmcturesofascastMgGdNd(GN)ternaryalloyswerecomposedoftheaMgmatrixandlamellartypeMg1砸eutecticphasesthecrystalstruc

5、tureofwhichWasnotabletobeidentifiedbyXRDanalysisWimtheincreaseofNdadditionthevolumefractionofeutecticphasesincreasedInthemeantimethedimensionofthematrixgrainsdecreasedandthedistributionofMg—I也phasesalsochangedfromdiscont

6、inuous(GN62)tocontinuous(GN64)networkalonggrainboundariesnevolumefractionoftheMgItEphaseinGN63alloyscontainingNdWasmuchhigherthanthatinG9alloyswithnoNdadditionSubstitutionofGdbvNdinMgREinterphaseresultedinthechangeofitsd

7、istributionfromthesecondphaseparticlestocontinuousnetworkAfterhotextrusiontheMgREphaseshowedfibrousandgranularmorohologicsalongthedirectionofextrusionHotextrusionalsesultedinthedynamicrecrystallizationinalloys，nleagingte

8、chniqueWasalsoinvestigatedinthepresentworkForthetwoseriesofalloysthepeakvalueofhardnessWasobtainedat200C／14h(G9)and225℃／12h(GN64)，respectivelyThemierostructureofG9andGN64alloysafterT5agingtreatmentWasinvestigatedbySEMand

9、TEMTheresultsshowedthattheplate—shapedlYprecipitatesformedfromthea—MgmatrixinG9alloys，whiletheneedle—shapedp”phaseandlYphaseprecipitatedsubsequentlyinGN64alloysBoth13“andB7existing_inG9andGN64alloyshadacertainorientation

10、relationshipwiththeIXMgmatrixHotextrusionresultedinsignificantincreaseoftensilepropertiesduetothedynamicrecrystallizationandworkhardeningSolidsolutionandaghagtreatmentofextrudedsamplesledtemarkableimprovementoftensilepro

11、pertiesaccountedbythecombinedeffectofsolidsolutionstrengtheningandagehardeningThestrengthsofaseastas—extrudedandagedspecimensofGNseriesalloyswerehigberthanMg6GdalloysduetotheadditionofNdelementIncomparison淅thG9alloys也eme

12、chanicalpropertiesofGN63WashigherbecauseoftwofactorsFirstlythesolidsolubilityofNdinmagnesiumWaslowel“thanGd’resultingintheincreaseofthevolumefractionofthesecondphaseinthealloysSecondlyNdadditionhadbettereffectongrainrefm

溫馨提示

  • 1. 本站所有資源如無(wú)特殊說(shuō)明，都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請(qǐng)下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等，如果需要附件，請(qǐng)聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶(hù)所有。
  • 3. 本站RAR壓縮包中若帶圖紙，網(wǎng)頁(yè)內(nèi)容里面會(huì)有圖紙預(yù)覽，若沒(méi)有圖紙預(yù)覽就沒(méi)有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 眾賞文庫(kù)僅提供信息存儲(chǔ)空間，僅對(duì)用戶(hù)上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理，對(duì)用戶(hù)上傳分享的文檔內(nèi)容本身不做任何修改或編輯，并不能對(duì)任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容，請(qǐng)與我們聯(lián)系，我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶(hù)因使用這些下載資源對(duì)自己和他人造成任何形式的傷害或損失。

評(píng)論

0/150

提交評(píng)論