Improved mechanical, wear and corrosion behaviour of nano-alumina reinforced electrodeposited Ni-P-Mo alloy coatings on HSLA steel

Nanoparticle reinforced ternary alloy coatings offer significant advancement in surface engineering applications. We hereby report on a unique system comprising alumina nanoparticle reinforced ternary Ni-P-Mo composite coatings electrodeposited onto HSLA steel substrates. Detailed characterisation showed exceptional enhancement of the mechanical, wear and corrosion resistant properties. An optimised alumina nanoparticle addition (0.3 g/L) drastically improved hardness up to 35.5% and reduced wear rate by around 11.52% compared to pure Ni-P-Mo coatings. Moreover, a significant reduction in corrosion rate in Ni-P-Mo/Al2O3 (0.3 mils/yr) was observed compared to Ni-P-Mo (4.8 mils/yr). However, the introduction of Al2O3 nanoparticles at concentrations exceeding 0.3 g/L seemed to have a detrimental effect on the coating morphology, leading to compromised mechanical strength, wear resistance and corrosion resistant properties.