Strengthening effect of inclusion of ZrC nano-ceramic particles on the corrosion and wear resistance of Ni-P electroless deposits

• Zirconium carbide (ZrC) affects the structure and properties of Ni-P coatings. • Ni-P/ZrC (1 g·L −1 ) coating has excellent corrosion and wear resistance. • Corrosion occurs and intensifies at coating defects. • Ni-P/ZrC coating has better long-term corrosion resistance. Zirconium carbide (ZrC) nano-ceramic particles were embedded in the nickel-phosphorus (Ni-P) nanocomposite coating on the surface of N80 steel through electroless deposition strategy. The addition of ZrC can significantly affect the surface morphology, microstructure, wear resistance and corrosion resistance of the coating. Compared with pure Ni-P coating, the average friction coefficient of Ni-P/ZrC (1 g·L −1 ) composite coating decreased from 0.510 to 0.224, and the specific wear rate is reduced from 1.31 × 10 −5 mm 3 ·m −1 ·N −1 to 2.81 × 10 − 6 mm 3 ·m −1 ·N −1 . In terms of improving the corrosion resistance of the coating, Ni-P/ZrC (1 g·L −1 ) composite coating shows a lower corrosion tendency and a higher electrochemical impedance, and its corrosion rate (4.54 × 10 −3 mm·a −1 ) is one order of magnitude lower than Ni-P coating (5.08 × 10 −2 mm·a −1 ). In addition, the long-term corrosion experiments of the samples show that the composite coating has a longer protective effect on the substrate. Through the analysis of the corrosion morphology, it is found that the improvement of the corrosion resistance of the coating is due to the addition of ZrC, which reduces the surface defects of the coating. At the same time, the labyrinth effect formed between ZrC and the coating can also slow down the corrosion rate.