Ignition-proof mechanism of magnesium alloy added with rare earth La from first-principle study
来源期刊：JOURNAL OF RARE EARTHS2012年第6期
论文作者：张国英 罗志成 张辉 褚冉
文章页码：573 - 578
摘 要：The surface segregation of La and its effect on the oxygen adsorption on a Mg（0001）surface for a coverageΘ=0.25 monolayer were performed by using first-principles calculations.The calculated results showed that La atoms preferred occupying surface sites to the bulk sites,which suggested the La surface segregation.When oxygen atoms adsorbed on a pure or La alloyed Mg（0001）surface,certain amount of heat would release,and La alloying made the heat released less,which might increase the ignition point of Mg alloy.Both Mg and La had strong atomic affinity with oxygen,so the oxidation film of Mg-La alloys consisted of MgO,La2O3.The denser La2O3 turned oxide film into fine and close structure,and prevented oxygen from passing through the oxidation film.The La-O covalent bonding could explain why La2O3 was compact,and resulted in good ignition-proof of Mg-La alloys.
张国英，罗志成，张辉，褚冉
College of Physical Science and Technoloy,Shenyang Normal University
摘 要：The surface segregation of La and its effect on the oxygen adsorption on a Mg（0001）surface for a coverageΘ=0.25 monolayer were performed by using first-principles calculations.The calculated results showed that La atoms preferred occupying surface sites to the bulk sites,which suggested the La surface segregation.When oxygen atoms adsorbed on a pure or La alloyed Mg（0001）surface,certain amount of heat would release,and La alloying made the heat released less,which might increase the ignition point of Mg alloy.Both Mg and La had strong atomic affinity with oxygen,so the oxidation film of Mg-La alloys consisted of MgO,La2O3.The denser La2O3 turned oxide film into fine and close structure,and prevented oxygen from passing through the oxidation film.The La-O covalent bonding could explain why La2O3 was compact,and resulted in good ignition-proof of Mg-La alloys.
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