【摘要】 采用金相显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)观察和硬度、导电率、力学性能检测等方法,研究了微量Sc、Zr及形变热处理对Al-Mg-Si合金组织与性能的影响。结果表明:添加质量分数分别为0.22%Sc和0.05%Zr的Al-Mg-Si合金铸态组织得到显著细化,枝晶组织基本得到消除;在350℃时效过程中,有大量的次生Al3(Sc,Zr)沉淀相析出,强烈地阻碍了位错运动和亚晶界迁移,显著强化了合金;在150℃时效过程中,有Mg2Si强化相析出,进一步强化合金;经600℃固溶+350℃时效+90%轧制变形+150℃时效的形变热处理工艺后,新型Al-Mg-Si-Sc-Zr合金的抗拉强度、硬度和导电率分别达到312 MPa、99 HV0.5和55.4%IACS,综合性能良好。更多还原

【Abstract】 Effects of trace Sc and Zr addition and thermomechanical treatment on microstructure and properties of Al-Mg-Si alloy were studied by optical microscopy( OM),scanning electron microscopy( SEM),transmission electron microscopy( TEM) and hardness,conductivity and mechanical property test. The results show that 0. 22% Sc and 0. 05% Zr( in mass fraction) addition can significantly refine grains of the Al-Mg-Si as-cast alloy and eliminate the cast dendrites. Secondary Al3( Sc,Zr) precipitates massively form in the process of aging at350 ℃,and strongly pin the movement of dislocation and sub-grain boundaries,which can effectively strengthen the alloy; strengthening phase Mg2 Si forms in the process of aging at 150 ℃,which can further strengthen the alloy. After 600 ℃ solid solution + 350 ℃ aging+ 90% rolling deformation + 150 ℃ aging thermo mechanical treatment,the tensile strength,hardness and electrical conductivity of the new Al-Mg-Si-Sc-Zr alloy are up to 312 MPa,99 HV0. 5 and 55. 4% IACS,respectively,the comprehensive properties is preferable.更多还原