Preparation method of nanometer coating for reducing marine organism adhesion on titanium alloy surface

Abstract

The invention discloses a preparation method of a nanometer coating for reducing the marine organism adhesion on a titanium alloy surface. Electrolyte further comprises a copper ammonia complex, which is prepared from copper sulfate and ammonium hydroxide, except for sodium phosphate, sodium silicate or boric acid; titanium alloy is conventionally treated and used as an anode; a stainless steel plate is used as a cathode; pulse power working current, duty cycle and pulse frequency are controlled at 10-20A, 10-20% and 500-650HZ respectively; the temperature of the electrolyte is controlled at 50 DEG C; a cuprous oxide Cu2O layer and a titanium dioxide TiO2 ceramic insulating coating in nanocrystal and amorphous structures are formed on the titanium alloy surface after electrolysis for 5-30 minutes; the coating is 5-50 microns in thickness, 400HV in surface hardness, 20MPa in binding strength, and 1 megohm in insulation resistance; no crack and no corrosion product are generated in a neutral salt mist corrosion test for 96 hours; the mass content of copper in the coating is not less than 5%; the marine organism adhesion weight after the titanium alloy is hung in seawater for 3 months is not greater than 20g / m<2>.

Description

technical field [0001] The application belongs to the technical field of oxidation coatings, in particular to a method for preparing nano-coatings for reducing the adhesion of marine organisms on the surface of titanium alloys. Background technique [0002] Microarc Oxidation is referred to as MAO for short. MAO is a new technology for in-situ growth of oxide ceramic coatings on the surface of non-ferrous metal substrates such as Al, Ti, Mg, Zr, Nb, Ta, etc., and alloys. Improve the corrosion resistance and wear resistance of the surface under the premise of improving the performance. Because the oxide ceramic coating has the characteristics of high bonding strength and good insulation, in the shipbuilding and marine industries, the use of MAO can be used in complex shapes and line sizes. A uniform and sufficiently hard coating is formed on very large parts to prevent galvanic corrosion of copper, copper alloys, steel pipes, piping accessories and other parts in contact with...

AI Technical Summary

Problems solved by technology

[0003] The commonly used electrolyte coating formula of MAO is phosphate, aluminate, silicate, glycerophosphate-acetate and sodium hydroxide solution system, and the prepared micro-arc oxidation coating does not have the ability to prevent marine organisms from adhering. For example, after three months of seawater hanging film test, the weight of marine organisms on the coating surface can reach 65-100g / m 2 , the greater the amount of marine organisms attached to the sea, the greater the blockage of the sea pipelines, pumps, valves and other components, and even cause serious corrosion in the joint gap, accelerate the corrosion damage of the base material, affect the normal use of the ship, and reduce the cost of the ship. safety and reliability

[0004] Chinese patent CN101311326A discloses an electrolyte and a micro-arc oxidation method for light metal micro-arc oxidation. The electrolyte contains 5-100g / L sodium hexametaphosphate, 2-100g / L sodium silicate, 0.1-10g / L Cobalt sulfate, 1-30g / L ammonium metavanadate, after micro-arc oxidation treatment, a micro-arc oxidation coating with good stain resistance, scratch resistance and compactness is obtained on the light metal surface, and has high hardness and wear resistance However, the micro-arc oxidation coating only has a certain antibacterial effect on single-celled organisms such as bacteria and fungi, and the ability to prevent marine organisms from adhering to light metal surfaces is very poor

[0005] So far, there are no relevant reports on the preparation method of nano-coatings that can reduce the adhesion of marine organisms to the surface of titanium alloys.

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