Electrostatic spraying technology of copper forgings in construction machinery is a common surface coating technology, which is used to provide protective, decorative or other functional coatings attached to the surface of the forgings. The following is a detailed explanation of electrostatic spraying technology and adhesion evaluation:
Electrostatic spraying technology:
Electrostatic spraying technology is a coating method by charging the sprayed material and spraying it directly on the surface of the object. The method uses the principle of electrostatic attraction between positive and negative charges to make the spray material uniformly deposited and attached on the forging surface under the action of the spray gun electric field to form a coating.
Electrostatic spraying technology has the following steps:
- Preparation: cleaning the surface of the piece, removing oil, dust and other impurities, to ensure that the surface is smooth.
- Spray material preparation: Select the appropriate spray material, and adjust and dilute it according to the manufacturer’s guidance to obtain the appropriate spray viscosity and fluidity.
- Spraying equipment Settings: According to the nature and requirements of the spraying material, adjust the parameters of the spraying equipment, such as the electric field of the spraying gun and the spray mode of the nozzle.
- Electrostatic spraying: Hold the spraying equipment, maintain the appropriate distance and Angle, and spray the surface of the forging in a uniform and continuous action.
- Curing treatment: curing treatment according to the requirements of the spraying material used, which can be carried out by natural drying or heating.
Adhesion evaluation:
Adhesion evaluation is the test of the strength of adhesion between the electrostatic spray coating and the forging surface. The adhesion directly affects the durability and working performance of the coating. Commonly used adhesion evaluation methods are as follows:
- Grid cutting method: Cut the surface of the coating into a grid shape, then paste the tape on it and tear it off quickly, and evaluate the adhesion by observing the position and area where the coating is torn off.
- Cross marking method: Use a knife to mark a series of cross lines on the surface of the coating, and then paste it with tape and tear it off quickly to evaluate the situation of the coating being torn off.
- Pressing method: Use a special adhesion tester to apply pressure on the surface of the coating to evaluate the adhesion between the coating and the substrate.
- Tensile test method: Fix one end of the coating on the fixture, apply tensile force, and evaluate the adhesion by measuring the force value of the coating being pulled off.
Adhesion evaluation is mainly a qualitative or quantitative description of the combination between the coating and the substrate, but the specific evaluation method needs to be selected according to the actual situation and demand. In addition, adhesion inspection and evaluation can be carried out in conjunction with relevant standards and specifications to ensure the quality and performance of electrostatic spraying coatings.
