| Abstract [eng] |
This research focuses on the electrodeposition and assessment of nanocrystalline and amorphous-like Fe-W alloys and Fe-W/Al2O3 composite coatings obtained from the environmentally friendly glycolate-citrate bath based on Fe(III) salt. The simulation of complexes distribution has been used to estimate the stability of newly developed electrolyte. The bath allows obtaining Fe-W coatings with a current efficiency up to 60-70%. The W content in alloys can be ranged from a few at.% to maximum 25 at.% of W by changing the deposition conditions. Increasing the W content in the alloy leads to the phase transformation from nanocrystalline mixture of Fe(W) solid solution and α-Fe to “amorphous-like” mixture of Fe2W intermetallic phase and W(Fe) solid solution. Accordingly, nanocrystalline Fe-W alloys have a combination of high saturation magnetization and relatively high hardness, which is suitable for the fabrication of various microelectromechanical systems; whereas amorphous-like Fe-W alloys and Fe-W/Al2O3 composite coatings with enhanced hardness and outstanding thermal stability are promising candidates for high-temperature applications. Electrodeposited Fe-W/Al2O3 composites can be considered an appropriate coating to use under dry conditions. Nevertheless, the corrosion resistance of Fe-W alloys and composites remains rather low, thus limiting their application for corrosion protection. However, a low corrosion resistance of Fe-W combined with the low saturation magnetization and high hardness is suitable for the fabrication of biodegradable metallic implants. |
