高镁Al-Mg系铝合金均匀化处理工艺  

Homogenization process of high magnesium Al⁃Mg series aluminum alloy

作　　者：马良 孙宁 马军星 陈同帅 郭丰佳 王经涛 Ma Liang;Sun Ning;Ma Junxing;Chen Tongshuai;Guo Fengjia;Wang Jingtao(National Engineering Research Center for Plastic Working of Aluminium Alloys,Shandong Nanshan Aluminium Co.,Ltd.,Longkou Shandong 265700,China;School of Materials Science and Engineering,Yantai Nanshan University,Longkou Shandong 265700,China)

机构地区：[1]山东南山铝业股份有限公司国家铝合金压力加工工程技术研究中心,山东龙口265700 [2]烟台南山学院材料科学与工程学院,山东龙口265700

出　　处：《金属热处理》2024年第6期100-105,共6页Heat Treatment of Metals

摘　　要：采用DSC、SEM、OM等技术手段对自行熔炼的高镁Al-6.5Mg-0.9Zn合金进行均匀化工艺研究,对合金过烧温度、晶粒形态及第二相组成等进行表征与分析。结果表明,Al-6.5Mg-0.9Zn合金铸态组织为类等轴晶组织,但晶界元素偏析严重,存在小区域的疏松缺陷。铸锭经435、442、449和456℃保温8 h的均匀化热处理之后,枝晶臂间距增大,晶粒尺寸由137.31μm增大至173.83μm,组织中残留相由连续分布转变为不连续分布,且组织中第二相含量由0.561%降至0.138%。经449℃保温8 h均匀化处理后的铸锭组织中未发现低熔点非平衡共晶相溶解峰,表明对于试验合金来说,以30℃/h升至449℃保温8 h的均匀化工艺最优。Homogenization process of self⁃melted high magnesium Al⁃6.5Mg⁃0.9Zn alloy was studied using techniques such as DSC,SEM and OM.The over heat temperature of the alloy,grain morphology and second phase composition were characterized and analyzed.The results indicate that the structure of the as⁃cast Al⁃6.5Mg⁃0.9Zn alloy is a quasi equiaxed crystal structure,but there is severe segregation of grain boundary elements and small areas of porosity defects.After homogenization treatment at 435,442,449 and 456℃for 8 h,respectively,the dendrite arm spacing increases and the grain size increases from 137.31μm to 173.83μm.The retained phase changes from continuous distribution to discontinuous distribution,and the content of the second phase decreases from 0.561%to 0.138%.After homogenization treatment at 449℃for 8 h,no low melting point non⁃equilibrium eutectic phase dissolution peak is found in the microstructure of the ingot,indicating that for the tested alloy,the optimal homogenization process is heating to 449℃at 30℃/h and holding for 8 h.

关 键 词：Al-Mg系铝合金 枝晶偏析 均匀化处理 显微组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]