论文部分内容阅读
利用Ca和碳质孕育对Mg3%Al合金进行复合变质处理,并研究了Fe及其Fe的添加顺序对细化效果的影响。与碳质孕育相比,Ca和碳复合孕育后的晶粒细化效果更为显著,Fe及其添加顺序对复合孕育细化效果无显著影响。Ca的添加可有效避免碳质孕育MgAl合金中因Fe所导致的晶粒粗化作用。在Ca和碳质复合孕育试样中可观察到大量的AlCO颗粒,这些颗粒实际应为Al4C3,并作为α-Mg的形核核心。然而,在熔体中添加Fe后,试样中可观察到大量在AlFe或AlCFe表面吸附Al4C3的双相粒子,该双相粒子可作为α-Mg的形核核心并导致晶粒细化。Ca有利于该双相粒子的生存,并与工艺条件无关,从而使得Fe对晶粒细化的“毒化”作用得到有效抑制,即Ca对Fe有“免毒化”效果。
The composite metamorphic treatment of Mg3% Al alloy was carried out by Ca and carbon inoculation, and the effects of addition order of Fe and Fe on the refining effect were studied. Compared with the carbon inoculation, the effect of grain refinement after Ca and C inoculation was more significant, and the order of addition of Fe and its addition had no significant effect on the compound inoculation and refinement. The addition of Ca can effectively prevent the grain coarsening caused by Fe in the carbonaceous inoculated MgAl alloy. A large number of AlCO particles were observed in Ca and carbon composite inoculated samples, and these particles should actually be Al4C3 and act as nucleation sites for α-Mg. However, after the addition of Fe into the melt, a large amount of two-phase particles of Al4C3 adsorbed on the surface of AlFe or AlCFe can be observed in the sample, and the two-phase particles can serve as nucleation sites of α-Mg and lead to grain refinement. Ca is conducive to the survival of the biphasic particles, and has nothing to do with the process conditions, so that the effect of Fe on the grain refinement “poisoning ” is effectively inhibited, that is, Ca has Fe effect on Fe.