Salt spray corrosion behavior and electrochemical performance of laser cladded Ni60-Ti3AlC2 composite coatings in 3.5% NaCl solution

Ni60-4%Ti3AlC2, -8%Ti3AlC2 and -12%Ti3AlC2 composite coatings were prepared on S355 steel by laser cladding, and the effects of Ti3AlC2 mass fraction on the corrosion behavior electrochemical performance of obtained coatings were analyzed using a salt spray corrosion test chamber and electrochemical workstation. The results show that the Ni60-Ti3AlC2 composite coatings are composed of Ti3AlC2, TixAly, Al4C3, Al3Ti and TiC phases, and their grains are refined with the increase of Ti3AlC2 mass fraction. The Ni60-12%Ti3AlC2 composite coating has the best salt spray corrosion resistance among the three kinds of coatings, which is attributed to the formations of & alpha;-Al2O3 and TiO2 oxide films The differences of diffusion rates between the Al and the Ti change the pH value near the anode and cathode of Ni60-Ti3AlC2 composite coatings, which is conducive to the formation of double-layer dense passive films to protect the composite coatings from further corrosion.