Article
Plasma Investigations
2022. V. 60. № 5. P. 599–606
Mahmoudi H., Hadavi S.M.M., Palizdar Y.
Plasma foil aluminizing of steel at a temperature below aluminum melting point
Annotation
In this research, steel AISI 4340 was aluminized by plasma foil, where the specimen was masked by an aluminum (Al–1.6 wt % Si) foil with a thickness of 50 μm and was placed in cathode position of glow discharge plasma reactor. By gradual increasing the pressure and voltage of plasma, cathode current rate increased that resulted in heating up of the specimen. The process was designed for sample treatment at 600∘C (below the melting point of aluminum), where for comparison, another experiment was also carried out at 750∘C. Aluminizing was conducted for about 5 min at process temperature. The coatings were characterized by field emission scanning electron microscopy equipped with energy dispersive spectroscopy and X‑ray diffraction. The coating consisted of a 90 μm-thick double layer of Al-rich FeAl3 and Fe2Al5 phases beneath Al during treatment at 600∘C. It is concluded that the effect of plasma was not only heating the sample but also providing the Al–steel diffusion couple and enhancing the interdiffusion of iron and aluminum elements in Al-rich iron aluminides. Plasma foil aluminizing at 750∘C resulted in the formation of a multi-layer coating consisting of iron aluminide phases (Fe2Al5 and FeAl) with a thickness of ∼140 μm. A comparison of the coating thickness obtained in this study with those reported in hot dip aluminizing showed that ions' bombardments on the sample surface during plasma process increased the coating thickness by activating the surface and enhancing the interdiffusion of iron and aluminum in aluminides.
Article reference:
Mahmoudi H., Hadavi S.M.M., Palizdar Y. Plasma foil aluminizing of steel at a temperature below aluminum melting point, High Temp., 2022. V. 60. № 5. P. 599
Mahmoudi H., Hadavi S.M.M., Palizdar Y. Plasma foil aluminizing of steel at a temperature below aluminum melting point, High Temp., 2022. V. 60. № 5. P. 599