资源描述:
《自蔓延高温合成氮化铝》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、JOURNALOFMATERIALSSCIENCE32(1997)5123Ð5126Self-propagatinghigh-temperaturesynthesisofAlNinagraphitecrucibleinairbymechanicalactivationTAKESHITSUCHIDA,TAKAOKITAGAWA,MICHIOINAGAKIDivisionofMaterialsScienceandEngineering,GraduateSchoolofEngineering,HokkaidoUniversity,North13We
2、st8,Kita-ku,Sapporo,060JapanPowdersofAlandCweremixedinamolarratioofAl:C"3:1andwerethengroundinaplanetaryballmill.Whenthethusmechanicallyactivatedmixturesweretransferredintoagraphitecrucibleandexposedtoair,theyspontaneouslyignitedandself-propagatinghigh-temperaturesynthesist
3、ookplaceintwosuccessivesteps.TheproductswereslicedalongthedepthdirectionandexaminedbyX-raydiffraction.Dependingonthedepthofthecrucible,aluminiumnitride,aluminiumcarbide,aluminiumoxynitride,aluminiumoxycarbideandalphaaluminaweredetected.Frommeasurementsofthelatticeconstant,i
4、twasfoundthataluminiumnitridewitha97%puritycouldbeobtainedatthebottomofthegraphitecrucible.1.Introductionofpowdertoballswasabout1:6.ThegrindingwasAluminiumnitride(AlN)andAlN-basedmaterialsinterruptedevery15min,andthesamplewascontainingO,C,Sie.g.,aluminiumoxynitride(AlON)scr
5、apedfromtheballsandthesidewallsofthejarand[1],aluminiumoxycarbide(AlOC)[2Ð4],alumi-thenreloadedandthegrindingrecommenced.The2niumoxynitridecarbide(AlONC)[2Ð4]andsialongroundsamplesweretransferredintoeitheraporce-(SiAlON)[1]haveattractedaconsiderableamountoflainsaucer(innerd
6、iameterof70mmanddepthofattentionforuseasadvancedceramics.Mechanical10mm)oragraphitecrucible(innerdiameterofactivationormechanosynthesisisapromisingprocess30mmanddepthof40mm)andallowedtoreactinfortheproductionoftheseAlN-basedceramics.Re-air.Thelumpofproductobtainedinthegraph
7、itecently,wehaveproposedanovelmethodforprodu-cruciblewascutintotheformofarectangularparal-cingaluminiumnitrideinairwhichis,inastrictsense,lelepiped(ca.10]10]12mminsize)andembeddedasolidsolutionbetweenAlNandAlOC,designatedintoepoxyresin.Then,asshowninFig.1itwassliced2as(AlOC
8、)(AlN)(x+0.8)[5].Thistechniqueisevery1or1.5mmalongthedepthofthegraphite21~xxbasedo