The Study On The Oxidation Kinetics Of The Rare-earth Magnesium Alloy

As the lightest constructional material, Mg alloy has high specific strength, high specific stiffness, good magnetic-shielding ability, good damping ability, and good mechanical property. Since its chemical character is very active, Mg alloy is prone to oxidation and burning, which makes it impossible to be melted and cast in air. Oxidation and burning of Mg alloy obstruct its application greatly. Fluxes and cover gases are currently used for the melting and production processes, and semi-solid thixocasting is also used to lower the operation temperature; but there still remain many problems. Alloying is a kind of promising method of preventing Mg alloy from burning.Alloying is used here to prevent Mg alloy from oxidation. The widely used Mg alloyZM5 is chose as the original alloy. On the surface of the molten alloy, a layer of protective film with dense structure is formed by the addition of mischmetal. The film prevents the penetration of oxygen and volatilization of Mg vapor, and then prevents the ZM5 alloy from oxidation and burning.X-ray diffraction (XRD), scanning electron microscope thermal gravitational analysis (TGA) was used to research the (SEM&EDS) and morphology and structure of oxide film, the distribution of ignition-proof element and oxidation kinetics at elevated temperature.The oxidation process and the composition of oxide film are analyzed, which gives a clear understand of oxidation at high temperature. It can help the oxidation-proof work of other metals and alloys. Alloying can improve the production efficiency, reduce environmental pollution and lower production cost, and then increase the application of Mg alloy.The rare earth ignition-proof Mg alloy will accelerate the production and application of Mg alloy and boost the development of magnesium industry. It willpromote the development of vehicle and electronics industries, which are adopting more and more Mg alloy parts. And it will also speed up the research and application of rare earth materials and the exploration of the abundant rare earth resources in China.