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建立了镁合金的晶体,液态及其固/液界面模型.采用递归法计算了Ca,Be在α-Mg、固/液界面、镁液态中的环境敏感镶嵌能,定义并计算了Mg,Ca及Be与氧的原子亲和能.计算结果表明:Ca,Be在镁晶体中的环境敏感镶嵌能较高,不能稳定固溶于晶体中,因此在固体中的溶解度较小.合金凝固时Ca,Be扩散到环境能较低的液体中,向液面聚集.由于Ca,Be与氧的原子亲和能低于镁与氧的亲和能,聚集在液体表面的Ca,Be将优先与氧结合,生成致密的镁与合金元素的混合氧化物,阻止镁合金燃烧.
The crystal, liquid and solid / liquid interface model of magnesium alloy were established.The environment-sensitive inlay energy of Ca and Be in Mg-Mg, solid / liquid interface and Mg liquid state was calculated by recursion method.The Mg, Ca And the atomic affinity between Be and oxygen were calculated.The results show that Ca and Be have high environmental sensitivity in the crystal of magnesium and can not be stably dissolved in the crystal and therefore have little solubility in the solid. , Be diffused into the environment can lower the liquid to the liquid surface accumulation.Because Ca, Be and oxygen atomic affinity is lower than that of magnesium and oxygen affinity, the accumulation of Ca, Be in the liquid surface will be preferential and oxygen Combined to produce a dense mixed oxide of magnesium and alloying elements, preventing the magnesium alloy from burning.