稀土变质与液态过热对共晶Al-Si合金凝固组织的影响

Effect of RE modification and superheating treatment on eutectic Al-Si alloy

采用稀土对共晶成分的 ZL 10 2合金进行变质处理 ,并对经稀土变质的铝合金熔体进行过热处理 ,用显微镜和扫描电镜对处理后的合金组织进行分析研究。试验结果表明 ,在金属型铸造条件下加入质量分数为 0 .4%～ 0 .8%的稀土对共晶Al-Si合金具有良好的变质效果 ,而在 960～ 10 60℃下的过热处理能使 RE变质后的共晶 Al-Si合金中的 Si相进一步细化 ,从而获得良好的凝固组织。

An alloy of eutectic ZL102 was modified with rare earth(RE), and the melt modified by RE was further superheated to the temperature much above its melting point. The microstructure of the alloys were investigated by means of microscope and SEM. The testing results showed that a significant modifying effect can be achieved in eutectic Al Si alloy in die casting by the addition of w(RE) being 0.4%~0.8%, furthermore, the Si in the modified alloy becomes finer after the alloy was superheated to 960~1 060 ℃. As a result, an optimum structure in Al Si alloy was obtained.