Fe-Al Intermetallics Prepared By Rapid Sintering

Fe-Al intermetallic compound is one of the most applied prospest aluminized intermetallics, with high thermal stability, high specific strength, oxidation resistance, corrosion-resistant and excellent mechanical properties under high temperature. However, because of the Fe-Al intermetallic compound materials with the brittleness, poor plasticity and toughness, low tensile strength, it is difficult to process and form, and it is not suitable for an important structure and high precision, complex components.Against the unworkability of Fe-Al intermetallic compound materials, the article showed that the preparation of Fe-Al intermetallics bulk by rapid sintering. The experimental equipment was the converted spot-welding machine of DN-16. The raw material powders of Fe, Al were mixed according the stoichiometric proportion of Fe3Al. The atomic percentage of Fe powders was 72%, Al powders 28%. The product's phase, microstructures, microhardness, density and stain resistance were measured and analyzed by X-ray diffraction (XRD), optical microscope (OM), microhardness tester and drainage. According the diffusion mechanics and the electric discharge mechanics, this paper discussed the sintering mechanism of rapid powder sintering. The experimental results showed that the green body, which was pressed by the forming pressure of 300MPa, was sintered for 3min at the sintering time of 8000A, and that the Fe-Al intermetallics with excellent properties were prepared. The average microhardness was 720HV.This method of sintering was different from traditional methods of powder sintering. Generally, the raw materials of traditional methods were the powders of Fe-Al intermetallics, which were prepared by MA, not mixed powders of Fe and Al. And the process of traditional methods was in vacuum or special atmosphere for a longer time. The process of this method was in the air for a short time, which indicated that technological conditions were simpler.Further researches based on this topic are significant for the problem that Fe-Al intermetallic compound materials are unmanageable, as well as the development and application of advanced materials in various fields.