预压缩镁板的冲压成形性能  

Stamping formability of pre-compressed magnesium sheets

作　　者：曹苗 赵崇斐 CAO Miao;ZHAO Chong-fei(College of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China;Bingzhou Intelligent Manufacturing Research Institute,Foxconn,Taiyuan 030000,China)

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024 [2]富士康并州智能制造研究院,山西太原030000

出　　处：《塑性工程学报》2024年第6期15-22,共8页Journal of Plasticity Engineering

基　　金：山西省基础研究计划青年科研项目(202203021222209);太原科技大学博士科研启动基金资助项目(20222081,20222109)。

摘　　要：对AZ31镁合金薄板沿不同方向预压缩相同变形量引入{1012}拉伸孪晶:第1组镁合金板沿轧向(RD)分别预压缩1%、3%和5%后再沿横向(TD)预压缩2%(命名为RT镁板:R1T2、R3T2和R5T2);第2组镁合金板沿TD预压缩2%后再沿RD预压缩1%、3%和5%(命名为TR镁板:T2R1、T2R3和T2R5)。对所有镁板在400℃下退火3 h,研究各预孪晶镁板的静态再结晶和冲压成形行为。结果表明:镁板预压缩变形量越大,孪晶越多;且在相同预压缩条件下,相比RT镁板,TR镁板中孪晶的体积分数更大。高温退火后,大预压缩程度的板材晶粒更加细小;且在相同预压缩条件下,相比RT镁板,TR镁板晶粒尺寸更加细小,分布更加均匀。随预压缩变形量的增加,镁板的屈服强度、极限抗拉强度和伸长率均增大;且相同预压缩条件下,相比RT镁板,TR镁板的屈服强度、极限抗拉强度和断裂伸长率更高。随着预压缩变形量的增加,镁板的杯突值显著增加;且相同预压缩条件下,相比RT镁板,TR镁板的杯突值更高,这很大程度上归因于其优异的延展性、较小的塑性应变比和较大的加工硬化指数。{1012}tensile twinning was introduced in AZ31 magnesium alloy sheets by pre-compressing along different directions with the same deformation.The first group of magnesium sheets were pre-compressed along rolling direction(RD)by 1%,3%and 5%,first,and then pre-compressed along TD by 2%(named RT magnesium sheets:R1T2,R3T2 and R5T2).The second group of magnesium sheets were pre-compressed along TD by 2%first,and then pre-compressed along RD by 1%,3%and 5%(named TR magnesium sheets:T2R1,T2R3 and T2R5).Then all magnesium sheets were annealed at 400℃for 3 h to study the static recrystallization and stamping formability behavior of each pre-twinning magnesium sheets.The results show that the larger the pre-compression deformation of magnesium sheets,the more twins.And the volume fraction of twinning in TR magnesium sheets is obviously large than that in RT magnesium sheets under the same precompression condition.After annealing at high temperature,the grain size of the magnesium sheets with the larger pre-compression deformation is finer.And the grain size of TR magnesium sheets is finer and more uniform compared with RT magnesium sheets under the same pre-compression condition.The yield strength,ultimate tensile strength and elongation of magnesium sheets increase with the increase of pre-compression deformation.The yield strength,ultimate tensile strength and elongation of TR magnesium sheets are higher than those of RT magnesium sheets under the same precompression.The Erichsen values of magnesium sheets increase significantly with the increase of pre-compression deformation.The Erichsen values of TR magnesium sheets are higher than that of RT magnesium sheets under the same pre-compression,which is closely attributed to the excellent ductility,small plastic strain ratio and large work hardening index.

关 键 词：预压缩 拉伸孪晶 静态再结晶 冲压成形性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]