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《初始取向?qū)Υ髴?yīng)變軋制AZ31鎂合金板材顯微組織和力學(xué)性能的影響-論文.pdf》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫。
1、第24卷第7期中國有色金屬學(xué)報(bào)2014年7月Volume24Number7TheChineseJournalofNonferrousMetalsJuly2014文章編號(hào):1004.0609(2014)07.1700.07初始取向?qū)Υ髴?yīng)變軋制AZ31鎂合金板材顯微組織和力學(xué)性能的影響董勇,劉吉兆(湖南工學(xué)院機(jī)械工程學(xué)院,衡陽421002)摘要:采用大應(yīng)變軋制技術(shù)對軋制面與擠壓板材ED—TE面分別成90。、45。和0。的AZ31鎂合金板材進(jìn)行加工,研究初始取向?qū)Π宀娘@微組織和力學(xué)性能的影響。結(jié)果表明:孿生誘發(fā)動(dòng)態(tài)再結(jié)晶是大應(yīng)變軋制過程中主要的再結(jié)晶機(jī)制,動(dòng)態(tài)再結(jié)晶的發(fā)生使合金晶
2、粒細(xì)化、力學(xué)性能大幅提高。軋制過程中孿生與板材初始取向密切相關(guān),通過改變初始取向可控制板材晶粒細(xì)化和強(qiáng)度改善效果。0。軋制試樣大應(yīng)變軋制過程中,大部分晶粒的c軸受壓,基面滑移啟動(dòng)難度增加,孿生的作用增強(qiáng),壓縮孿晶密度增大,進(jìn)而通過孿生誘發(fā)動(dòng)態(tài)再結(jié)晶獲得更為細(xì)小的再結(jié)晶組織和更為優(yōu)異的力學(xué)性能。壓下量為80%時(shí),0。軋制板材的平均晶粒尺寸為5m,抗拉強(qiáng)度、屈服強(qiáng)度和伸長率分別為311.4MPa、202.6MPa和26.9%。關(guān)鍵詞:AZ31鎂合金;大應(yīng)變軋制;初始取向;孿生;動(dòng)態(tài)再結(jié)晶;力學(xué)性能中圖分類號(hào):TG146.2文獻(xiàn)標(biāo)志碼:AEffectsofinitialorien
3、tationonmicrostructureandmechanicalpropertiesofAZ31magnesiumalloysheetsfabricatedbylargestrainrollingDONGYong,LIUJi—zhao(SchoolofMechanicalEngineering,HunanInstituteofTechnology,Hengyang421002,China)Abstract:LargestrainrollingwascarriedoutonAZ31magnesiumalloywithdiferentorientationswhichwa
4、smachinedfromanextrudedsheetalonganglesof90。,45。and0。totheED·TEplane,andtheefectsofinitialorientationonthemicrostructureandmechanicalpropertiesofthesheetswereinvestigated.Theresultshowthattwininduceddynamicrecrystallization(DkX)isthemainDRXmechanismduringlargestrainrolling,whichconsequentl
5、yresultsinthegrainrefinementandimprovementofmechanicalproperties.Twinningissensitivetoinitialorientationduringrolling,therefore,thegrainrefinementandimprovementofmechanicalpropertiescanbecontrolledbyalternatinginitialorientation.Thebasalslipisdificulttoactivateduringlargestrainrollingof0。s
6、pecimenduetothecompressionstressappliedonthec—axisofmostgrains.Therefore,theroleoftwiningenhanced,especiallycompressiontwinning,consequentlyresultsinmuchfinerDRXgrainsandmuchbettermechanicalproperties.Theaveragegrainsizeof0。specimenatrollingreductionof80%is5,andtheultimatetensilestrength(U
7、TS),yieldstrength(YS)andelongationofthesheetsare311.4MPa,202.6MPaand26.9%,respectively.Keywords:AZ31magnesiumalloy;largestrainrolling;initialorientation;twining;dynamicrecrystallization;mechanica1properties鎂合金作為最輕的金屬結(jié)構(gòu)材料之一,具有比強(qiáng)好,電磁屏蔽性能強(qiáng),且易于回收等優(yōu)點(diǎn),被譽(yù)為21度和比剛度高,導(dǎo)熱