Preparation And Study Of Corrosion Behaviour In Marine Environment Of Fe₃Al Intermetallics Compound

The Fe-Al intermetallic alloy research beginning to the 20thcentury 30's, it studies several passes through the fluctuation,obtains the breakthrough in the end of 70's of the 20th century, to the 20th century 80's, the Fe-Al alloy had been taken a kind of structural material obtains the widespread research.Fe₃Al intermetallics, with super-lattice structure, possess metallic bond,covalent bond and ion bond in binding mode. The unique structure determines the special mechanical properties. Fe₃Al intermetallics were of considerable interest in the high temperature creep property, and the high temperature strength and , magnetic and electro thermal applications. Its high temperature creep property, and the high temperature strength are higher than most metallic.Meanwhile the oxidation and corrosion resistance are higher than most metallic materials else, materials, and the higher thermal conductivity and plasticity than ceramics.As a new kind of cheap material with low density whose properties are between alloys and ceramics, they are regarded as semi-metallic and semi-ceramic materials. Meanwhile, Fe₃Al intermetallics have favorable wear resistance else.Fe₃Al intermetallics powder was achieved through high energy ball milling of blended elemental Fe and Al powders in this paper.The structural evolution of Fe-Al elemental powders during mechanical alloying process under the protection of argon atmosphere and low temperature annealing process, and the microstructure and mechanical properties of bulk Fe₃Al have been investigated by means of XRD and DSC.The results show that disorderedα-Fe solid solution formed during milling. The reduction of crystal size and the increase of microstrain exist simultaneity, and the microstrain increased with the increasing of mill time. The disorderα-Fe solid solution milled for 60h translates to order DO3 structure through Al atom order rearrangement and removing of APS domains during annealing at 800℃. The bulk Fe₃Al were prepared by hot-pressed vacuum sintering.In recent years, with the land resources dried up along day after day,the research and the development of sea material already was imminent.There are lots of microorganisms in seawater. When immersed in seawater,surface of metals will soon be covered by a layer of biofilm. The Fe₃Al material is corroded in the sea water, can have the quiteobvious pitting corrosion; Exposes probably 10 days can appear the obvious corrosion in the sea water, the surface appears the biofilm; to 180 days, appears the disintegration phenomenon; in the antiseptic sea water only appears the yellowthe loose rust level; Indicated the microorganism corrodesin is acting the important role.At the same time, the material also can receive in the sea water thesoluble salty anion function, all these factors can change the metalsurface electrochemistry condition , these changes finallycauses the spoiled occurrence. Therefore the research and the development new sea-related material is very important and essential!By using polarization measurement, electrochemical impedance spectrum(EIS), scanning electron microscopy(SEM) to reveal the electrochemical behavior of Fe₃Al intermetallics. Thus opens up the (Fe₃Al) material the application scope.