变质Al-x Mg2 Si合金中超细初生Mg2 Si的制备

在未变质Al-xMg2 Si合金中,随着Mg\Si含量从18wt.％降低到14wt.％,初生Mg2 Si晶粒尺寸发生明显细化,由～30μm减小到～10μm;当合金中Mg\Si的含量降低到12wt.％,初生Mg2 Si相完全消失,其金相组织为单一共晶相组成.对Al-xMg2 Si合金进行0.5wt.％Ca-Sb复合变质处...

Preparation of Ultrafine Primary Mg2 Si in Modified Al-Mg-Si Alloy

Al-xMg₂Si alloy was modified with 0.5 wt.% Ca-Sb. With the decrease of Mg/Si content from 18 wt% to 14 wt%, the grain size of primary Mg₂Si in the unmodified alloy was refined from ~ 123 mm to ~ 15 mm, and the grain size of primary Mg₂Si in the unmodified alloy decreased from ~ 123 mm to ~ 12 mm When the content of Mg/Si in the alloy is reduced to 10 wt%, the microstructure of the alloy is composed of primaryα- Al + eutectic Mg₂Si. In Al-xMg₂Si alloy modified by 0.5 wt.% CA sb, dendrite like primary Mg₂Si disappears and transforms into fine polygon due to the effect of modifier. With the decrease of Mg/Si content from 18 to 12 wt.%, the grain size of primary Mg₂Si decreases from ~ 15 mm to ~ 5 mm, forming ultrafine primary Mg₂Si. The mechanical properties of the alloy were tested, and it was found that ultrafine primary Mg₂Si had a great effect on improving the mechanical properties of the alloy. The optimum alloy is Al-12Mg₂Si modified by 0.5 wt.% Ca-Sb.