原铝液DC铸造2A12铝合金铸锭的高温均匀化研究  

Study on high temperature homogenization of DC-cast 2A12 aluminum alloy ingot produced with electrolytic aluminum melt

作　　者：孙振宇 冯彦波 聂波 李瑞锋[2] 赵刚[2] 田妮[1,2,3] 

机构地区：[1]山东兖矿轻合金有限公司,山东邹城273515 [2]东北大学材料各向异性与织构教育部重点实验室,辽宁沈阳110819 [3]兖矿集团有限公司博士后科研工作站,山东邹城273515

出　　处：《轻合金加工技术》2012年第8期27-32,共6页Light Alloy Fabrication Technology

基　　金：国家自然科学基金项目(51001022);中央高校基本科研业务费项目(110410003)资助

摘　　要：针对原铝液DC铸造制备的2A12铝合金铸锭,利用金相显微镜、扫描电镜及其附带的能谱分析仪、电导率测定、DSC测定分析及拉伸试验研究了其铸态显微组织,以及高温均匀化工艺对合金铸锭显微组织、轧材力学性能及电导率的影响。结果表明,原铝液DC铸造2A12铝合金铸锭的铸态组织具有明显的树枝晶状特征,其中α-Al构成树枝晶晶干,块状Al2Cu和AlFeMnCu合金相及具有明显共晶组织特征的层片状S相Al2CuMg均分布于晶干间;合金铸锭在490℃均匀化保温8 h之前,可溶合金相回溶入基体的速度很快,490℃均匀化时间超过12 h以后,可溶合金相回溶入基体的速度很慢,490℃均匀化处理保温时间延长至36 h,合金基体中仍残留大量低熔点合金相;497℃24h高温均匀化处理不能完全消除合金基体中低熔点产物,但经497℃12 h均匀化处理后合金基体中残留低熔点合金相量较经490℃36 h均匀化处理后合金基体中残留低熔点合金相量更少;497℃均匀化保温时间由12 h延长至24 h对其热轧板力学性能及电导率无明显提高作用。The casting microstructure of DC cast 2A12 aluminum ingot prepared with elec-trolytic aluminum melt has been observed, and the effect of high temperature homogenization on microstructure, mechanical properties and electrical conductivity of hot rolled2A12 alumi-num alloy sheet have been investigated by using of optical microscopy, SEM/EDS, conductiv-ity inspection, DSC analysis and tensile experiment. The results show that there are dendrite crystal features, and in which there are α-A1 becomes the trunks of dendrite crystals, while the A12Cu,AIFeMnCu blocky phases and the AI2CuMg lamellar S phases with distinct eutec-tic pattern are all distributed along the inter-dendrite trunk evenly. The soluble phases dis-solve into matrix very quickly when the alloy ingot being homogenized at 490℃ with no more than 8h holding,whereas the dissolving rate of soluble phases ,is slow down when the ingot being homogenized at 490℃ with more than 12h holding. There are still some soluble phases remained in the alloy matrix after the ingot being homogenized at 490℃ with 36h holding, e-verl the homogenization is gong at 497 ℃ with 24h holding, the low temperature soluble pha- ses can not be eliminated thoroughly. But the amount of the remained soluble phases in the matrix of alloy ingot after homogenization at 497℃ with 12h holding is less than those of the alloy ingot after homogenization at 490℃ with 36h holding. There are no noticeable improve- ment effects on both the mechanical properties and the conductivity of the hot-rolling 2A12 alloy sheet when the homogenization holding time is prolonged from 12h up to 24 h.

关 键 词：原铝液 DC铸造 2A12铝合金 均匀化 显微组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG292[金属学及工艺—金属材料]