资源描述:
《az31镁合金轧制箔材微气压胀形变形规律的研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、哈尔滨工业大学工学硕士学位论文AbstractWiththeongoingminiaturizationinproducts,thereisagrowingdemandforthedevelopmentofaccurateformingprocessformechanicalmicro-parts.Gasblowmicro-bulgingisannoveltechnologytomanufactureverysmallmetalparts,inparticularforbulkproduction.Inrecentyears,gasblowmicro-b
2、ulginghavebecomeahotspotinthefieldofmicroforming.Inthispaper,aseriesofexperimentswerecarriedouttostudythedeformationlawofgasblowmicro-bulgingforAZ31Bmagnesiumalloyrolledfoil.TheAZ31Bmagnesiumalloyrolledfoilswith0.1mminthichnessofdifferentgrainsizewereacquiredthroughtheheattreatme
3、ntprocessatthetemperatureof245℃.Themodelofgraingrowthwasbuildedbythewayofregression.Thefoilswithdifferentthichnessofuniformgrainsizewereacquiredthroughtheheattreatmentprocessattheuniformheatingtemperatureanddifferenthealingtime,thegrainsizeisapproximately2μm.Theinfluenceofthegasp
4、ressure,bulgingtemperature,initialgrainsize,foilthicknessanddiameterofdiecavityonformabilityofgasblowmicro-bulging(thebulgingheight)wereinvestigatedusinghemispherefreebulgingtests.Theexperimentalresultsshowedthattheoptimumbulgingtemperatureis380℃,intherangeofforminggaspressure,th
5、ebulgingheightofthehemispherepartsincreasedwiththeincreaseoftheforminggaspressure,thebiggestbulgingheightof682μmandheighttodiameterratioof0.718wereobtainedat380℃、4.2MPawithin15min;Usingthefoilswhichwassubjecttotheheattreatmentat245℃wereusedtostudytheinfluenceofthegrainsizeonforma
6、bilityofgasblowmicro-bulging,whenthegrainsizegetsmaller,theformabilityofthegasblowmicro-bulgingisbetterandtheheightofhemispherepartsishigher;Whenthegrainsizekeepsconstant,thethinnerthethicknessoffoils,thehigherthebulgingheight;Whenthehemispherepartsareingoodcondition,theheighttod
7、iameterratioincreasedwiththeincreaseofthediameterofdiecavity.Onthebasisofabovestudy,cylinderbulgingtestswereperformedwithcombineddieThedeepthofdieinternalcavitywasadjustablewiththeadjustablememorandumsale.Theperfectcylinderwasacquiredwithcombineddieat380℃、4.2MPa.Theheightofthecyl
8、inderis510μmandtheradiusofbottomcorneris