均匀化退火工艺对7075铝合金微观组织的影响研究  

Effect of Homogenization on The Microstructure of 7075 Aluminum Alloy

作　　者：闵爱武 Min Aiwu(Fujian Nanping Aluminum Co.,Ltd.,Nanping 353000,Fujian;Key Laboratory of Aluminum Alloy Enterprises in Fujian Province,Nanping 353000)

机构地区：[1]福建省南平铝业有限公司,福建南平353000 [2]福建省铝合金企业重点实验室,福建南平353000

出　　处：《福建冶金》2025年第2期41-44,共4页Fujian Metallurgy

基　　金：大规格高强高韧7XXX铝合金铸锭成形关键技术研发(2020T3031);。

摘　　要：采用光学显微镜、扫描电镜(SEM)和差示扫描量热法(DSC)等研究了工业半连续铸造的7075合金在单级和多级均匀化退火过程中的组织演变。结果表明:7075合金铸态组织中包括非平衡共晶α-Al+Mg(ZnCuAl)_(2)、含Cr相、含Fe相、Mg_(2)Si、Al_(7)Cu_(2)Fe相等。铸态中第二相的面积百分比为5.26%,经470℃/24 h的均匀化退火后,因非平衡共晶相的回溶或转变,下降到2.24%,并基本保持稳定,此时S相并未彻底消除。然而,经(470℃/12 h)+(485℃/12 h)的双级均匀化退火后,第二相的面积百分比进一步下降到2.05%,表明双级均匀化工艺相比传统的单级具有更好的效果。The microstructure evolution of 7075 alloy after industrial semi-continuous casting during single stage and two-stage homogenization treatment was studied by optical microscopy,scanning electron microscopy(SEM)and differential scanning calorimetry(DSC).It was found that the as-cast microstructure of 7075 alloy contains non-equilibrium eutecticsα-Al+Mg(ZnCuAl)_(2),Cr-containing phase,Fe-containing phase,Mg_(2)Si and Al_(7)Cu_(2)Fe phase.The area percentage of the second phases in the as-cast state is 5.26%.After homogenization at 470℃/24 h,it decreases to 2.24%and remains stable,which is due to the dissolution or transformation of the non-equilibrium eutectics.Under this condition,the S phase has not been completely eliminated.However,after homogenization at 470℃/12 h+485℃/12 h,the area percentage of the second phases further decreased to 2.05%,indicating that two-stage homogenization treatment is better than the traditional single stage homogenization.

关 键 词：7075铝合金 均匀化退火 半连续铸造 微观组织 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG156.2[金属学及工艺—金属材料]