| The 21 st century is a high standards of materials age which tend to develop high performance,excellent material, low cost, and meet the environmental requirements of the new materials,magnesium plays a more and more important role in this century. A series of superior performance characteristics of magnesium alloy, such as qualitative light, heat conduction performance, high strength, high specific rigidity, makes it become a hot materials in many fields. But magnesium alloy also has some difficult problems to be solved. According to the chemical properties of magnesium alloys is lively, it is easy to oxidation to form a layer of porous oxide film, then aggravate the alloy corrosion rate, serious hinder the further development and application of magnesium alloy in industry.How to solve this problem effectively, has been promoted to a hot and difficult problem in the field of magnesium alloy.Active chemical properties are rare earth,s feature, and the melting point of RE is greater than900℃, the melting point of aluminium alloy is 660℃, so high melting point will cause a certain degree of RE burning loss. If direct adding rare earth metals in aluminium alloy liquid, it can also lead to the serious loss of rare earth metals, wasting the resources, increase the cost, and it is difficult to add in RE uniformity, so add rare earth into aluminium alloy usually takes the form of intermediate alloy to ensure the rare earth can give full play to the role.The main contents of the artical are as follows:(1) Al- Sm master alloy prepared by liquid cathode electrolysis which is belong to th one of active cathode alloying method. Adding Al(aluminum rods as liquid cathode) into Sm F3 Li F- Sm2O3 molten salt system under different temperature, different Li F concentration, different cathodic current density, the electrolysis time is 30 min. Studied the influencing factors of current efficiency. Using ICP, XRD, SEM and EDS to analyze Al- Sm alloy.(2) Modification effects of Sm on AZ91 D alloy. The contents of Sm are 0.1%, 0.4%, 0.7%, 1.0%respectively. The analysis methods are OM observation, XRD analysis, SEM and EDS analysis.The experimental methods are weightlessness corrosion test, potentiodynamic polarization curves.Mainly studying the effect of Sm on corrosion resistance of alloy.(3) Modification effects of preparation method(vacuum melting and ordinary melting) on AZ91D+1.0%Sm alloy. The contents of Sm are 1.0% respectively. The analysis methods are OM observation, XRD analysis, SEM and EDS analysis. The experimental methods are weightlessness corrosion test, potentiodynamic polarization curves. Mainly studying the effect of Sm on corrosion resistance of alloy.(4) Modification effects of single rare earth elements Sm and composite rare earth element La, Ce,Sm on AZ91 D alloy. The content of Sm is 3.0%, the content of La is 1.0%, the content of Ce is0.7%. The analysis methods are OM observation, XRD analysis, SEM and EDS analysis. The experimental methods are weightlessness corrosion test, potentiodynamic polarization curves.Mainly studying the effect of single rare earth elements Sm and composite rare earth element La,Ce, Sm on corrosion resistance of alloy. |
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