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In this work, nickel-cobalt-phosphorus composites co-deposited with three different particles (aluminium oxide, silicon nitride and silicon carbide) were, respectively, prepared on ASCM20 + 5Fe aluminium alloy by electroless plating. The effects of the different reinforcement particles on the morphology, composition, microstructure, microhardness, wear resistance and corrosion resistance of composites were investigated. The results show that the largest incorporation amount of particles in number density, the finest grains, the highest microhardness, the best wear resistance and the lowest average friction coefficient are found to occur on the silicon carbide reinforced coating. The best corrosion resistance is observed on the coating co-deposited with aluminium oxide.

Ternary Ni‐Co‐P/TiN (20 nm) nanocomposite coatings with Co content in the range of 0–23 wt% were successfully co‐deposited on Al alloys by electroless plating. The morphology, composition, microstructure, micro‐hardness, wear behavior, and corrosion properties of the coatings were tested using SEM, EDS, XRD, Vickers hardness, ball‐on‐disc wear tester, and electrochemical workstation, respectively. The effect of Co content on the tribological and corrosion properties of Ni‐Co‐P/TiN coatings was studied. It is found that all the coatings have a compact and rough granular structure with sub‐micro globules non‐uniformly distributed on the surface. The grain size and the content of Ni and P decrease, but the micro‐hardness, adhesion force, friction coefficient, and corrosion resistance correspondingly enhance with the increase of Co content in Ni‐Co‐P/TiN coatings. The improved corrosion resistance of Ni‐Co‐P/TiN coating is due to the passivation behavior and small grain caused by the introduction of Co. Based on the excellent properties on the wear and corrosion resistance, ternary Ni‐Co23‐P/TiN coating with high Co content, may be applied as an optimum protective coating for Al alloys.