Investigation of Erosion–Corrosion Resistance of Electroless Ni–P–Ti Composite Coatings

Electroless Ni–P–Ti composite coatings were prepared on AISI 1018 steel substrates by incorporating three different amounts of Ti nanoparticles into a Ni–P matrix. Erosion–corrosion tests were performed on AISI 1018 steel, Ni–P and Ni–P–Ti coatings. AISI 1018 steel exhibits the lowest erosion–corrosion resistance, while the highest erosion–corrosion resistance is achieved on coating containing 15.2 wt% Ti. For AISI 1018 steel, removal of oxide film by abrasive particles and severe pitting corrosion are the dominant erosion–corrosion mechanisms. For Ni–P coating, cracking and fracture of the coating are the prominent degradation mechanisms. However, micro-cutting, micro-ploughing and micro-indentation are the principal mechanisms for Ni–P–Ti coatings. Ti particles act as barriers during the erosion–corrosion process, which improve the erosion–corrosion resistance of the composite coatings. © 2020, Springer Nature Switzerland AG.