镁合金熔体净化工艺的研究

Purification Technique of Regenerated Magnesium Alloy Melt

研究了镁合金再生过程中熔体内夹杂物含量、尺寸与静置时间的关系,以及主要合金成分和杂质元素含量的变化规律。应用Stokes公式模拟了夹杂物沉降距离与静置时间的关系,分析了影响夹杂物沉降速度的因素。结果表明: 在镁合金废料完全熔解后静置5-10 min,可以将熔体内夹杂物的含量降至0.5%以下,夹杂颗粒尺寸小于0.3 mm ,234 熔剂的精炼效果好于RJ-1熔剂,经234熔剂精炼后静置8min,镁合金熔体中的夹杂物含量降至0.02%以下,夹杂颗粒尺寸小于10μm。夹杂物沉降速度与夹杂半径的平方、夹杂密度成正比,与镁合金液粘性系数及镁合金液密度和夹杂密度的比值成反比。

The relationship between time and content and size of inclusions in regenerated magnesium alloy melt is researched. The rules of content changes of main alloy components and impurity elements are studied. The relationship between deposition distance and time is simulated by Stokes equation. The influence factors of deposition velocity of inclusion are analyzed. The results show that the inclusion content could be reduced less than 0.5% and inclusion size could be reduced less than 0.3mm if the melt is stewed for 5 to 10 minutes after fusion completely. The refining effect of 234 flux is better than RJ-1 flux. The inclusion content could be reduced less than 0.02% if the melt is stewed for 8 minutes after refined by 234 flux and inclusion size could be reduced less than 10 μm. The deposition velocity of inclusion is directly proportional to its square diameter and density, and inversely proportional to melt viscosity coefficient and the ratio of melt density and inclusion density.