CeCl_3对含Ce镁合金精炼过程中Ce损耗量的影响

Effect of CeCl_3 on loss of Ce in magnesium alloy during refining

采用含CeCl3的净化熔剂对含Ce的镁合金进行精炼,研究了CeCl3对合金中Ce损耗量的影响规律。结果表明:当熔剂中不含CeCl3时,合金中的Ce损失高达27.7%;而当CeCl3的含量达到15%时,合金中的Ce损失仅为4.5%,CeCl3处理使镁合金中稀土相均匀分布,使Mg17Al12相细化,但相组成没有明显变化;随着CeCl3含量的增加,合金力学性能提高,但过多的CeCl3会在合金中引入熔剂夹杂。并从热力学方面探讨了熔剂与镁液的作用机理,计算了镁熔体中Mg和Ce的活度及熔剂熔体中MgCl2和CeCl3的活度。结果表明,由于CeCl3抑制了合金中Ce与熔剂中MgCl2的反应,从而降低了Ce的损耗。

The effect of CeCl3 in flux on the loss of Ce in magnesium alloy during refining was investigated. The results show when there is no CeCl3 in the flux, the loss of Ce in the magnesium alloy AZ91 is 27.7%. When CeCl3 is added by 15% in the flux, the loss of Ce is only 4.5%, CeCl3 can also make Ce-containing phases distribute evenly and Mg17 Al12 phase refine, but the phase composition of the experimental alloys can not change obviously. The mechanical properties of the alloys are improved by CeCl3 processing with the increase of CeCl2 content, and excessive CeCl3 will produce flux inclusions. Furthermore, the reactions between flux and magnesium melt were studied thermodynamically. The activities of Mg and Ce in magnesiun alloy and MgCl2 and CeCl3 in flux were calculated. The results show that CeCl3 restrains the reaction between Ce in magnesium alloy and MgCl2 in flux. Therefore, the loss of Ce in magnesium alloy decreases.