(1. 东北大学 材料科学与工程学院，沈阳 110819；
2. 东北大学 材料各向异性与织构教育部重点实验室，沈阳 110819；
3. 东北大学 金属型线材研究中心，沈阳 110819)
摘 要: 利用金相显微镜(OM)、透射电子显微镜(TEM)结合万能材料试验机研究Sc含量(质量分数)从0.034%增大至0.215%时，Sc含量对T6态Al-10Zn-2.5Mg-1.6Cu-0.15Zr铝合金板材中过剩结晶相、弥散相、析出相、晶粒及力学性能的影响。结果表明：Sc含量从0.034%增加至0.215%，T相和Al7Cu2Fe相过剩结晶相粒子组态无明显变化；纳米级Al3(Sc,Zr)弥散相粒子的尺寸不变但数量呈现出先增多后减少的趋势；析出相粒子尺寸先细化后粗化，数量先增多后减少。当Sc含量为0.189%时，合金板材中出现3~5 μm的初生Al3(Sc,Zr)粒子，其数量随Sc含量增加而增多。T6态Al-10Zn-2.5Mg-1.6Cu-0.15Zr-(0.034-0.139)Sc合金板材的晶粒呈纤维状，且随Sc含量增加，纤维状晶粒逐渐细化、长度逐渐缩短；当Sc含量为0.189%时，合金板材发生明显再结晶，其晶粒均为细小类球状等轴晶；当Sc含量从0.034%增加至0.215%，T6态合金板材的强度和伸长率均随Sc含量增加呈现出先升高后降低的趋势；当Sc含量为0.139%时，合金板材的性能最佳，其抗拉强度、屈服强度和伸长率分别为701 MPa、665 MPa和8.0%。
关键字: ScZr复合合金化；高Zn超高强铝合金板材；显微组织；力学性能
（1. School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China;
2. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China;
3. Research Center for Metallic Wires, Northeastern University, Shenyang 110819, China）
Abstract:The effects of Sc content from 0.034% up to 0.215% on the constituent, dispersoid, precipitate, grain and mechanical properties of Al-10Zn-2.5Mg-1.6Cu-0.15Zr aluminum alloy sheet in T6 temper were investigated by OM, TEM and universal material testing machine. The results show that, with the increase of Sc content from 0.034% to 0.215%, there is no obvious change with the size and quantity of micron T phase and Al7Cu2Fe in Al-10Zn-2.5Mg-1.6Cu-0.15Zr alloy sheet under T6 temper, the size and number of nanoscale precipitate is firstly refined and increase and then coarsened and decrease, whereas the number of the nanoscale Al3(Sc,Zr) dispersoid increases with its size unchanging. When Sc content is 0.189%, there is primary Al3(Sc,Zr) with the size of 3-5 μm in the alloy sheets, and its number increases but the size has no obvious change with the increase of Sc content up to 0.215%. The grains of Al-10Zn-2.5Mg-1.6Cu-0.15Zr-(0.034-0.139)Sc alloy sheets in T6 temper are fibrous, and the fibrous grain gets thinner and shorter with the increase of Sc. When the Sc content is more than 0.189%, the grains of Al-10Zn-2.5Mg-1.6Cu-0.15Zr-(0.189-0.215)Sc alloy sheets in T6 temper are fine equiaxed which means that the recrystallization behavior of alloy sheet is promoted. When Sc content increases from 0.034% to 0.215%, the strength and elongation of alloy sheets in T6 temper firstly increase and then decrease. The alloy sheet in T6 temper with 0.139% Sc has the optimal performance with the tensile strength, yield strength and elongation of 701 MPa, 665 MPa and 8.0%, respectively.
Key words: composite micro-alloying with ScZr; high-Zn ultra high strength aluminum alloy sheet; microstructure; mechanical property
