Mg-Ca合金在空气和火焰环境下的高温抗氧化性

High-Temperature Oxidation Resistance of Mg-Ca Alloys in Air and Under Flame Exposure

摘要:

研究了Mg-Ca合金在空气和火焰环境下的氧化行为和机理。结果表明，对于空气中的氧化，高Ca含量Mg-Ca合金表面形成的具有Ca积聚层的Mg-Ca-O氧化膜和低的Mg蒸汽压，表现出良好的保护效果。然而，Mg₂Ca上氧化膜的脱落导致了进一步的氧化。因此，高Ca含量的Mg-Ca合金仅显示出良好的保护效果。对于在火焰环境下的氧化，熔融合金释放出了Ca原子并向外扩散，在高Ca含量的Mg-Ca合金中形成具有高Ca含量积聚层的Mg-Ca-O氧化膜。尽管熔融合金中Mg蒸汽压很高，但具有高Ca积聚层的Mg-Ca-O氧化膜仍显示出优异的保护效果。

Abstract:

The oxidation behavior and mechanism of Mg-Ca alloys in air and under flame exposure were studied. Results show that for the oxidation in air, the Mg-Ca-O oxide film with Ca accumulation and low Mg vapor pressure on the surface of Mg-Ca alloys with high Ca content shows good protective effect. However, the falling off phenomenon of the oxide film on Mg₂Ca results in the further oxidation. Hence, the Mg-Ca alloys with high Ca content only show good protective effect. For the oxidation in flame, the molten alloys release the Ca atoms to diffuse outward. The Mg-Ca-O oxide film with high Ca accumulation layer forms in Mg-Ca alloys with high Ca content. Despite the high Mg vapor pressure in the molten alloy, the Mg-Ca-O oxide film with high Ca accumulation layer shows excellent protective effect.