Method for preparing tungsten carbide coating on surface of roller for lithium battery production

Abstract

The invention relates to a method for preparing a tungsten carbide coating on the surface of a roller for lithium battery production. The method comprises the following steps of (1) carrying out visual inspection and magnifying glass inspection on the surface of the roller for lithium battery production; (2) after the surface of the roller is subjected to oil removal, impurity removal and purification, conducting rough grinding and texturing treatment on the surface of the roller through a rough polishing machine; (3) carrying out protection treatment on the non-spraying surfaces at the two ends of the roller subjected to rough grinding and texturing by adopting a high-temperature-resistant adhesive tape and a tool; and (4) using liquid-phase propane as a main combustion gas, using compressed air as a combustion-supporting gas, using nitrogen as a carrier gas powder feeding gas, inputting all the gases into a combustion chamber through a porous ceramic sheet, initially igniting by a spark plug for high-pressure combustion, generating high-velocity flames with the flame flow speed being more than 7 times of the sound velocity, spraying tungsten carbide powder on the surface of the roller to be sprayed by adopting a powder flame spraying technology, and rapidly cooling and solidifying to form the tungsten carbide coating; and (5) carrying out fine polishing treatment on the surface of the roller sprayed with the tungsten carbide coating by adopting a fine polishing machine.

Description

technical field [0001] The invention relates to the technical field of lithium battery production, in particular to a method for preparing a tungsten carbide coating on the surface of a roll used for lithium battery production. Background technique [0002] With the deepening and development of scientific research and industrial application, surface engineering technology is generally divided into three fields: surface coating technology, surface penetration technology and surface treatment technology. Surface coating technology is to apply liquid paint on the surface of the material, or deposit the plating atoms on the surface of the material, so as to obtain a coating or plating layer that is different in crystal structure, chemical composition and performance from the base material. Such technologies include coating , surfacing, thermal spraying, electroplating, chemical plating and vapor deposition, etc.; surface diffusion technology is to infiltrate (or ion implant) ato...

AI Technical Summary

Problems solved by technology

Although the hardness of existing forged alloy steel rolls can reach above HRC62, the individual particles of the positive electrode material and negative electrode material of the lithium battery are very hard during drying. The fatigue layer, especially the continuous extrusion of the positive pole piece through the coating particles, will leave slight indentations on the roll surface, and the surface quality of the roll will continue to decline. Generally, it will be more serious after 25-30 days of use. When the indentation is serious When the quality of the pole piece is affected to a certain extent, the roll must be replaced to avoid affecting the surface of the battery pole piece; at the same time, some pole piece materials will form electrochemical corrosion with some components in the alloy steel, which will also accelerate the decline in the quality of the roll surface

However, due to the extremely complicated grinding of the roll change, the replacement and grinding precision requirements are high, the waste of time is large, and the maintenance cost is high. Moreover, after 5-12 times of roll grinding, the hardened layer on the surface of the roll is removed, resulting in the scrapping of the roll

Images