Effect of Temperature on the Corrosion Resistance of Ni5Al Coating Deposited by Electric Arc in 3.5% NaCl Solution

The electrochemical behavior of the Ni5Al coating deposited by an electric arc was evaluated. Its behavior was evaluated in a saline solution as a function of temperature (20 degrees C, 40 degrees C, and 60 degrees C). The variation as a function of time of the Ni5Al coating's values of open circuit potential, linear polarization resistance, and the evolution of its electrochemical impedance spectra were analyzed. With this deposition technique, the rapid formation of thick coatings is achieved, which reduces the presence of interconnected porosity. Even though the microstructural characteristics showed the presence of trapped oxides, the electrochemical measurements carried out showed excellent corrosion resistance of the coating. The coating quickly develops a passive layer that allows it to rapidly reach thermodynamic equilibrium with the corrosive medium.

Automated summary

The electrochemical behavior of Ni5Al coating deposited by electric arc was evaluated in a saline solution at different temperatures. The variation over time of open circuit potential, linear polarization resistance, and electrochemical impedance spectra of the coating were analyzed. Despite the presence of trapped oxides in the microstructure, the coating showed excellent corrosion resistance and rapidly formed a passive layer to achieve thermodynamic equilibrium with the corrosive medium.