NOUFERROUS METALLURGICAL EQUIPMENT

Aluminum-manganese (Al-Mn) alloy possesses good plasticity, weldability and corrosion resistance, thus showing broad application prospects for corrosion protection of steel. Herein, the electrodeposition behavior of Al-Mn is investigated by cyclic voltammetry and chronopotentiometry in the ionic liquid electrolyte composed by 1-ethyl-3-methylimidazolium chloride, aluminum chloride and manganese chloride. Scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction techniques are employed to compare the surface morphology, elemental composition, and crystal structure of Al-Mn coatings electrodeposited at different current densities. The corrosion resistance of Al-Mn coatings in the simulated seawater is evaluated using open circuit potential and potentiodynamic polarization curves. Meanwhile, the effects of annealing temperature and time on the surface morphology and anti-corrosion ability of Al-Mn coatings are also studied, systematically. The results demonstrate that Al-Mn coating undergoes a structural transformation from amorphous state to crystalline state with the increase of current density. Among them, the amorphous coating displays a better corrosion resistance than the crystalline counterpart, while appropriate heat treatment can further improve its anti-corrosion property.