Effect of Ti3SiC2 content on the corrosion behavior of Al/Ti3SiC2 composite coatings

The purpose of this study was to investigate the electrochemical corrosion properties of flame-sprayed Al and Al/(5, 10, 15)% Ti₃SiC₂ coatings in a 3.5% NaCl solution. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used for analyzing the microstructural characteristics of the coatings. For examining the corrosion behavior of the coatings, a potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) were used. After the potentiodynamic polarization test, the SEM micrograph of coatings indicated that Ti₃SiC₂ particles played a significant role in pitting corrosion. The results of potentiodynamic polarization tests revealed that Al/Ti₃SiC₂ coating is nobler than that of the pure aluminum coating. On the contrary, the addition of Ti₃SiC₂ particles reduced the process of thickening the passive layer. The results of the EIS tests demonstrated that the presence of Ti₃SiC₂ particles significantly enhances the corrosion resistance of the coatings.