【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3～5μm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%。更多还原

【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 from0.034%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 3-5μm 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 701MPa,665 MPa and 8.0%,respectively.更多还原