Mackenzieetal.Thedeformation,recrystallisationandtextureofthreemagnesiumalloyextrusions
7Inversepole guresforextrusionaxisdirectionshowingbulktexturesofasextrudedandannealedAZ31,WE43and
ZC71:aAZ31asextruded,bZC71asextruded,cWE43asextruded,dAZ31annealed,eZC71annealed,fWE43annealed
DiscussionsweepacrossamicrostructuretoproducenewstrainfreeAsextrudedmicrostructuresgrains.Similarpartiallyrecrystallisedmicrostructures
havebeenreportedinAZ31hydrostaticallyextrudedat
IntheextrudedmicrostructuresshowninFigs.2–5the300uC.3
grainsaresmallerthanthoseobservedintheannealedInextrudedZC71(Fig.3),theLABsdissectingthedirectchillcastbillets(Fig.1a–c)becauserecrystallisa-unrecrystallisedregionsmaybedeformationinducedtionhasoccurredduringextrusion.Thebimodalgrainboundaries.InextrudedWE43(Fig.4),HABsextendsizedistributionsarisebecausetheextrusionsareacrosstheunrecrystallisedregion.TheseHABsarepartiallyrecrystallised;thelargegrainsinthecentreofparalleltooneanother,althoughEBSDdataindicatesFigs.2–5areunrecrystallised,whilethesmallergrainsthattheydonothavetwinorientation.Theymaybearerecrystallised.Theunrecrystallisedgrainscontainedkinkbands25thathavearisenasaresultofhighcom-asubstructureconsistingofahighdensityofLABsthatpatibilitystressesgeneratedingrainboundaryregions.developedduringdeformation.MostofthesurroundingLABsform,andasdeformationcontinues,themisor-smallrecrystallisedgrainscontainlittleornodeforma-ientationacrosstheseboundariesincreasesuntiltheytionsubstructurebecauseduringrecrystallisationHABsbecomeHABs.Deformationinducedboundaries,
suchTable2Tensileandcompressive0?2%yieldstrengthsandtensile/compressive0?2%yieldstrengthratios,forAZ31,
WE43andZC71inasextrudedandannealedconditions
AsextrudedAnnealed
Tensile,MPaCompressive,MPaRatioTensile,MPaCompressive,MPaRatio
AZ31170871325113251150ZC71213.63199.551..3010663141WE43185.28183.91.07222
101.6494.
10893.282.36
115780.94
MaterialsScienceandTechnology2007VOL23NO101177