Optimisation and analysis of jet impingement erosion behaviour of composite titanium based electroless nickel ENi-P coated naval steel (AH36)

This paper aims to address the impact of jet impingement on nano titanium-based ENi-P composite coatings deposited through electroless deposition on AH36 steel through Taguchi design of experiments. L9 Taguchi DOE was utilised to synthesise nine coatings by varying the four process parameter combinations suggested by the technique. Jet impingement combined with AFS 50/70 quartz sand erosion experimental run was conducted on the acidic, alkaline and nine ENi-P-TiO2 composite coatings administered through a waterjet erosion tester. The influence of C14-SB type Zwitterionic surfactant and nano TiO2 were discussed along with temperature and bath pH to achieve better resistance against the jet impingement on the surface of the coatings. Analysis of variance, the S/N ratio, and interaction plots were used to determine the optimal bath input parameters to deliver the least weight loss from the erosive environment and identify its use in the marine environment. The proposed optimal coating was validated using a confirmation test, and the weight loss was reduced by more than 35% compared to the initial condition parameter (A2B2C2D2). In addition to mechanical properties, the quality of the deposits was analysed through morphological and chemical composition probed through scanning electron microscope, energy dispersive X-Ray analysis and powder X-Ray diffraction methods. As a result, the Composite Modified Resilience (CMR) value of ENi-P-TiO2 optimal coating was improved by over 41.17%, and its corresponding weight loss was reduced to 35% compared to the initial condition. This experiment paves the way for further study on electroless deposits and their characteristics on AH36 steel generally used for shipbuilding in commercial ships, naval, and marine associated defence applications.