Calciumhexaluminate(CA6)wassynthesizedbymixinglight-weightcalciumcarbonateandAl2O3micropowder(calcinedα-Al2O3,activatedα-Al2O3orρ-Al2O3)accordingtothestoichimetricratioofCA6,andreactionsinteringat1200,1300,1400and1500℃for3h,respectively.Effectsofthethreealuminamicropowdersonthephasecomposition,microstructureandpropertiesofCA6wereinvestigated.Theresultsshowthat:(1)forthethreeAl2O3micropowders,thereactiontogenerateCA6inspecimensbasicallycompletesatabout1500℃;CA6generatedinallspecimensisplanar,butthearraymodesareslightlydifferent;(2)thespecimenspreparedfromcalcinedα-Al2O3orρ-Al2O3shrinkalmost,whilethespecimenspreparedfromactivatedα-Al2O3expand;(3)thecoldcrushingstrengthofthespecimenpreparedfromactivatedα-Al2O3isthehighest,reaching42.5MPawhenonlyCA6exists(afterfiringat1500℃);(4)thespecimenpreparedfromρ-Al2O3hasthelowestgenerationtemperatureofCA6andthehighestapparentporosity,reaching70.1%whenonlyCA6exists(afterfiringat1500℃);(5)thespecimenpreparedfromcalcinedα-Al2O3hasthebiggestbulkdensity.
