顆粒狀Mg2Si增強過共晶Al-20％Si基復(fù)合材料的制備.pdf

1、分類號：密級：學(xué)號：2007130單位代碼：10407碩士學(xué)位論文論文題目:顆粒狀顆粒狀Mg2Si增強過共晶增強過共晶Al20%Si基復(fù)基復(fù)合材料的制備合材料的制備研究方向AlSi基復(fù)合材料的研究與制備專業(yè)名稱材料學(xué)研究生姓名陳明導(dǎo)師姓名、職稱劉政教授2009年11月13日江西贛州IIAbstractParticlereinfcedaluminummetalmatrixcompositeshavemanyexcellentmechani

2、calpropertiesphysicalpropertiessuchashighspecificstrengthspecificstiffness，resistantwear，antifatigue，lowthermalcoefficientofexpansion，etcTheywillincreasinglybeusedinmanyfieldssuchasaeronautics，astronautics，automobileelec

3、tronsoonInthispaper，theMg2SiparticlereinfcedhypereutecticAl20%SialloyinsitucompositesaremanufacturedbyDMR(DirectMeltReaction)ThemostcastingtechniqueparameterofMg2SiAlSicompositeshasbeeninvestigatedThedifferentMg2Siconten

4、t(10%、12%、15%、18%、20%)ofMg2SiAlSicompositeshasbeenmanufacturedbyaddingdifferentcontentsofmagnesiumThecomplexmodificationof20%Mg2SiAlSicompositeshasbeenconductedbyaddingdifferentcontentsofPLaAftercomplexmodification，heatt

5、reatmentwasusedtothe20%Mg2SiAlSicompositesThehardnesswearresistanceofMg2SiAlSicompositeswereinvestigatedTheresultsoftheresearchareasfollows：(1)ThegrainsofMg2Siprimarysiliconinthecompositesbecomefineatthepouringtemperatur

6、e750℃Withtheincreaseofthecoolingrates，themicrostructurethehardnesswearresistanceofthecompositeareobviouslyimprovedTheoptimalcastingtechniqueparameterwas：thepouringtemperatureis750℃，coolinginthewater(2)WiththecontentofMg2

7、Siincreasing，themphologyofprimaryMg2SiintheMg2SiAlSicompositeshaschangedfrompolygonblocktoacterslikefinallybecomecoarsedendrite(3)ThecomplexmodificationofPLahaschangedthemphologysizeoftheprimaryMg2Siin20%Mg2SiAlSicomposi

8、tesWithadding0.1%P0.54%La，themphologyoftheprimaryMg2Siinthemicrostructurehaschangedfromcoarsedendritetosmallsphericalparticles，thesizeofprimaryMg2Sidecreasedtoabout14μm(4)ThemodificationmechanismofPwasobtained，namelyAlPi

9、nthemeltcouldbeasthenucleusofprimaryMg2Si，whichcanacceleratethenucleationofprimaryMg2SirefinementtheprimaryMg2SiThemodificationmechanismofLawasthatLacouldfmsomewhiteneedlephasesomerichareaofLa，whichcanabsbinthegrowthfron

10、toftheprimaryMg2Si，changetheinterfaceenergyofprimaryMg2Siinhibititsanisotropicgrowth，reachtheeffecttochangethemphologyofprimaryMg2Si(5)Complexmodificationhasimprovedthehardnesswearresistanceofthe20%Mg2SiAlSicompositesThe