大应变轧制Mg-Al-Sn合金板材的微观组织与力学性能  

Microstructure and Mechanical Properties of Mg-Al-Sn Alloy Sheet Produced by Large Strain Rolling

作　　者：莫华均[1] 程仁山 马立峰[4] 林金宝[4] 杨吉顺 潘虎成 任玉平 秦高梧[2,3] MO Huajun;CHENG Renshan;MA Lifeng;LIN Jinbao;YANG Jishun;PAN Hucheng;REN Yuping;QIN Gaowu(The First Sub-institute,Nuclear Power Institute of China,Chengdu 610041;School of Materials Science and Engineering,Northeastern University,Shenyang 110819;Key Laboratory for Anisotropy and Texture of Materials,Northeastern University,Shenyang 110819;Heavy Machinery Engineering Research Center of the Ministry of Education,Taiyuan University of Science and Technology,Taiyuan 030024)Abstract:A new wrought magnesium sheet alloy,the Mg-3Al-1Sn alloy(AT31)with both high strength)

机构地区：[1]中国核动力研究设计院第一研究所,成都610041 [2]东北大学材料科学与工程学院,沈阳110819 [3]东北大学材料各向异性与织构教育部重点实验室,沈阳110819 [4]太原科技大学重型机械教育部工程研究中心,太原030024

出　　处：《机械工程学报》2020年第2期56-62,共7页Journal of Mechanical Engineering

基　　金：国家重点研究发展计划(2016YFB0701200);国家自然科学基金(51525101,U1610253,515010322)资助项目.

摘　　要：通过对Mg-3Al-1Sn合金(AT31)进行挤压以及后续的单道次大应变量轧制变形,得到强度和塑性兼备的新型变形镁合金板材。组织分析表明,AT31合金中析出了一定数量的Mg17Al12相和Mg2Sn相,挤压态合金经轧制之后晶粒均得到有效的细化,因此合金的强度显著提高。经250℃低温轧制后,AT31合金的晶粒尺寸细化最明显,单道次约58%应变量之后晶粒尺寸约4.72μm;随着应变量提升至约66%,AT31合金的晶粒尺寸略有长大,约4.94μm。经300℃下轧制之后,最低晶粒尺寸可达到约5.58μm;同样,随着应变量的增加,晶粒尺寸先显著降低后有所上升。与此对应,这与拉伸所测的屈服强度变化规律完全一致的,即符合经典的细晶强化理论。经过250℃温度下的单道次约58%大应变量轧制变形后,Mg-3Al-1Sn合金板材的抗拉强度及伸长率匹配性最优,屈服强度约185 MPa,抗拉强度约256 MPa,伸长率约29.2%,具备优异的强塑性兼备特性。鉴于此,Mg-Al-Sn合金在工业中有着广阔的应用潜力。A new wrought magnesium sheet alloy,the Mg-3Al-1Sn alloy(AT31)with both high strength and high ductility,was obtained by first extrusion and subsequent single-pass large-strain rolling processing.The microstructure analysis showed that the certain amounts of Mg17Al12 phases and Mg2Sn phases were precipitated in the AT31 alloy,and the grains of the as-extruded alloys were effectively refined after rolling,and the strength was significantly improved.After low-temperature rolling at 250℃,the most obvious grain size refinement is detected in the AT31 alloy.The grain size was reduced to be about 4.72μm after a single pass of about 58%deformation.As the deformation is increased to about 66%,the grain size of the AT31 alloy slightly grows,about 4.94μm.After rolling at 300℃,the minimum grain size can reach about 5.58μm.Similarly,with the amount of deformation increasing,the grain size significantly decreases firstly and then increases.The grain size change is in accordance with the variation of yield strength,which further corresponds to the classical grain refinement hardening theory.The Mg-3 Al-1 Sn alloy sheet which is rolled by a single pass to about 58%at 250℃,exhibits the optimal combination of tensile strength and elongation.The yield strength,the ultimate strength and the elongation of as-rolled AT31 alloy are about 185 MPa,about 256 MPa,about 29.2%,respectively.Therefore,Mg-Al-Sn alloy has a broad application potential in the industry.

关 键 词：镁合金 轧制变形 动态再结晶 第二相 晶粒细化 

分 类 号：TG146[一般工业技术—材料科学与工程]