简介：AZ31Mg合金的微观结构进化在变化隧道期间，尖挤出(CCAE)被调查。AZ31Mg合金的谷物在在523K使变形的CCAE以后从500m显著地被精制到15m。脱臼在挤出的起始的阶段被导致，他们自己重排在变丑期间形成脱臼边界和亚谷物边界。当通过有紧张的水平变化隧道的标本增加了时，亚边界演变到高角度谷物边界(HAGB)。谷物精炼的过程能被描述为连续动态恢复和再结晶(CDRR)。

简介：Equalchannelangularpressing(ECAP)processingandannealingwereappliedtotheAZ31magnesiumalloysheetstoevaluatethepotentialimprovementinthemechanicalpropertiesandformability.TheECAPexperimentwasconductedat300℃inadiehavinganincludedangleof90obetweentwochannelsbytheBCZroutewiththesheetsrotatedby90°aboutthenormalaxisofplateplane.Thetensiletestsandconicalcuptestswereconductedatvarioustemperaturesfrom20to250℃.Theexperimentalresultsindicatedthatimprovingtheworkingtemperaturescouldleadtothesoftinthematerialandtheenhancementofductility.Comparatively,theECAPedAZ31alloysheetsshowedtheloweryieldstrengthandsmallerconicalcupvalue(CCV)thantheunECAPedcounterpartintheroomtemperature.Thedifferenceinyieldstrengthbetweenthembecamesmallintheelevatedtemperature,buttheECAPedsamplesstillhadthesmallerCCVvalue,implyingtheimprovedformability.ThetextureoftheAZ31alloysheetscouldbemodifiedbyECAPandthedecreaseintheyieldstrengthandmoreuniformdeformationrealizedinthematerial,sotheformabilityofAZ31alloysheetswasimproved.

简介：Anas-castmagnesiumalloywithhighAlcontentMg15Alwassubjectedtoequal-channelangularpressing(ECAP)throughadiewithanangleofφ=90?at553KfollowingrouteBc.Itisfoundthatthenetworkβ-Mg17Al12phasesintheas-castMg15Alalloyarebrokenintosmallblocksanddisperseduniformlywithincreasingnumbersofpressingpasses.Moreover,manynano-sizedMg17Al12particlesprecipitateintheultra-fineα-Mgmatrix.Thegrainsareobviouslyrefined.However,thegrainstructureisinhomogeneousindifferentareasofthealloy.Theaveragesizeoftheprimaryphaseα-Mgisreducedtoabout1μmwhilegrainsofaround0.1-0.2μmareobtainedinsometwo-phaseareas.WithadditionalECAPpasses(upto8),coarseningofthegrainsoccursbydynamicrecovery.RoomtemperaturetensiletestsshowthatthemechanicalpropertiesofMg15Alalloysaremarkedlyimprovedafter4ECAPpasses.Theultimatetensilestrengthandelongationtofailureincreasefrom150MPato269.3MPaandfrom0.05%to7.4%,respectively.Comparedwiththatafter4passes,theelongationtofailureofthealloyincreasesbutthestrengthofthealloyslightlydecreasesafter8ECAPpasses.FracturemorphologyoftheECAP-processedalloyexhibitsdimple-likefracturecharacteristicswhiletheas-castalloyshowsquasi-cleavagefractures.