Cu-Sc中间合金在液态Al-Zr合金中的溶解

Dissolution of Cu-Sc Master Alloy in Liquid Al-Zr alloy

摘要:

本文研究了Cu-20wt%Sc中间合金在液态Al-0.12wt%Zr合金中的溶解行为。发现随着保温温度提高和保温时间延长,含Sc质点的尺寸减小,面积分数降低,Al₃Zr相质点尺寸也减小,面积分数也降低。凝固后在α Al基体中的Sc、Cu和Zr的固溶量随保温时间延长和保温温度提高都增加。保温一定时间后,部分溶解到溶体中的Sc原子被吸附到Al₃Zr相表面,形成中间为Al₃Zr相表面富Sc的结构。Sc和Zr联合加入后,合金凝固组织细小,随着保温温度提高和保温时间延长,合金凝固组织的晶粒尺寸略有增大。大量表面富Sc的Al₃Zr质点为合金凝固提供了大量的异质形核核心,细化了合金组织。添加Cu-Sc中间合金的Al-Zr合金,均匀化退火后,同添加Al-Sc-Zr中间合金一样,也析出大量“芯壳”结构的Al₃(Sc,Zr)相。

Abstract:

Dissolution behaviors of Cu-20%Sc master alloy in liquid Al-0.12%Zr alloy was studied in this paper. It was found that both size and areal fraction of particles bearing Sc and Al₃Zr particles decreased,the solubility of Sc,Cu and Zr in α Al increased with increase in holding time and temperature. Part of Sc atoms was odsorbed on the surface of Al₃Zr particles so that Al₃Zr particles rich Sc on surface were formed. The microstructure of the alloy with Sc and Zr after solidification was fine observably. Average grain size of the alloy increased slightly with increase in holding time and temperature. Fine microstructure of the alloy with Zr and Sc is resulted from the a lot of stable nuclei of Al₃(Zr,Sc) particles rich Sc on surface. Same as adding Al-Sc-Zr master alloy Al₃(Sc,Zr) precipitated in the Al-Zr alloy added by Cu-Sc master alloy after homogenization.