High-binding-force uniform coating for surface of hydraulic valve rod and preparation method of high-binding-force uniform coating

The invention provides a high-binding-force uniform coating for the surface of a hydraulic valve rod and a preparation method of the high-binding-force uniform coating. The coating consists of 60 to 80 percent of aluminum oxide nanoparticles, 10 to 25 percent of silicone resin and 5 to 15 percent of organic silicon coupling agent. The diameter range of the alumina particles is 10-50nm, and the molecular weight of the silicone resin is 500-2000Da. The preparation method comprises the following steps: (1) mixing aluminum oxide particles, silicone resin and an organic silicon coupling agent in a closed container to form a uniform pre-coating material; (2) polishing and chemically cleaning the hydraulic valve rod to ensure that the surface is smooth and clean; (3) coating the pre-coating by adopting a spraying, dipping or spin coating method and the like, and keeping the thickness of the coating within a range of 10-50 microns; and (4) the hydraulic valve rod coated with the pre-coating is cured at the constant t