Method for removing tungsten carbide wear-resistant coating

Abstract

The invention relates to a technology of metal surface coating removal, in particular to a method for removing a tungsten carbide wear-resistant coating. According to the method for removing the tungsten carbide wear-resistant coating, a chromic anhydride electrolyte is utilized, the tungsten carbide wear-resistant coating on the surface of an aluminum alloy is removed in an electrolysis manner, and a chromic acid anode oxide film is formed on the surface of the aluminum alloy. The chromic anhydride concentration of the chromic anhydride electrolyte ranges from 20 g / L to 70 g / L, and the electrolytic voltage ranges from 19.5 V to 50 V. According to the method, the electrolytic removal rate of the coating can be controlled by controlling the voltage in the electrolytic process; and meanwhile, after the tungsten carbide coating is completely removed, the anode oxide film flayer ranging from 0.002 micrometer to 0.005 micrometer is formed on the surface of the aluminum alloy, the aluminum alloy cannot be electrolyzed, and part basic damage can be controlled to be 0.01 mm or below.

Description

technical field [0001] The invention relates to a metal surface coating removal technology, in particular to a method for removing a tungsten carbide coating on an aluminum alloy. Background technique [0002] Aviation parts often use lightweight aluminum alloys, but aluminum alloys are generally not wear-resistant. In order to achieve their functional properties, it is often necessary to spray a layer of tungsten carbide coating on the surface of aluminum alloys. The hardness of the coating is very high, and some local damage phenomena such as local pinholes and brittle peeling often appear during the production and processing process. Once the local damage of the coating occurs, the coating is generally removed by grinding, but with this This method will not only damage the base material of the part, but once the grinding wheel touches the base material, the aluminum alloy with good ductility will also be bonded to the grinding wheel, making further grinding impossible. A...

AI Technical Summary

Problems solved by technology

The hardness of the coating is very high, and some local damage phenomena such as local pinholes and brittle peeling often appear during the production and processing process. Once the local damage of the coating occurs, the coating is generally removed by grinding. This method will not only damage the base material of the part, but once the grinding wheel touches the base material, the aluminum alloy with good ductility will also stick to the grinding wheel, making it impossible to grind further

At present, once the tungsten carbide coating on aluminum alloy parts of existing aviation products is damaged, it is generally downgraded or scrapped.