Al-Cu-Mg-Ag-Er合金晶界相组成及生长方式  

Phase Constitution and Growth Manner at Grain Boundary in Al-Cu-Mg-Ag-Er Alloy

作　　者：李云涛[1] 刘志义[1] 马飞跃[1] 夏卿坤[1] 

机构地区：[1]中南大学,湖南长沙410083

出　　处：《稀有金属材料与工程》2008年第6期1019-1022,共4页Rare Metal Materials and Engineering

基　　金：国家'973'重点基础研究发展项目(2005CB623705-04)

摘　　要：研究了Al-4.0Cu-0.45Mg-0.4Ag-0.25Er合金铸态晶界相的组成及其生长规律。结果表明:稀土Er在合金中主要以Al8Cu4Er相的形式存在,Mg和Ag固溶于α-Al。合金铸态组织由α-Al固溶体、Al8Cu4Er相和Al2Cu相组成。Al8Cu4Er相和Al2Cu相共生于α-Al固溶体晶界,形成离异型共晶组织。凝固过程中,Al8Cu4Er相优先依附于先共晶相α-Al形核,并且分别以枝晶生长和平面生长这2种方式有选择的进行生长,形成α-Al、Al8Cu4Er相和Al2Cu相的三元共晶组织。The phase constitution at grain boundary in as cast Al-Cu-Mg-Ag-Er alloy has been studied in this paper. The casting structure of experimental alloy is dominated by dendritic α-Al solid solution and interdendritic eutectic structure including Al8Cu4Er phase and Al2Cu phase. Most of Er segregate at grain boundaries and form a primary Al8Cu4Er phase, a few dissolve in the a-Al matrix. The growth manner research results in more detail reveal that the Al8Cu4Er phase grows up separately in dendritic growth and small planar growth due to the different supercooling degrees decided by bath composition. During non-equilibrium freezing, the cast structure is dominated by AlsCu4Er/A1ECU binary eutectic and α-Al/Al8Cu4Er/Al2Cu ternary eutectic.

关 键 词：Al—cu—Mg-Ag合金 稀土Er 三元共晶 生长方式 

分 类 号：TG146.21[一般工业技术—材料科学与工程]