Painting diecast aluminum is a commonly used aluminum alloy surface treatment method. The process mainly uses a paint spray gun to spray paint on the surface of die-cast aluminum parts in order to beautify the appearance, protect the surface, and improve corrosion resistance. In the production process of aluminum alloy die casting, painting diecast aluminum as a kind of indispensable link can effectively improve the quality of die casting aluminum parts and value-added products and further broaden the application field of aluminum alloy. In this paper, we will introduce the product characteristics of painting diecast aluminum, the use of methods and precautions, and other aspects of the content.
First, the product background
Aluminum alloy has the characteristics of light weight, high strength, strong plasticity, easy processing, etc. Therefore, it has been widely used in automobiles, aviation, electronics, construction, and other fields. In these fields, aluminum alloy parts not only need to meet the basic performance requirements but also need to have a good appearance and corrosion resistance. In order to achieve these requirements, surface treatment has become an essential part of the production process of aluminum alloy parts. As a common tratamento de superfície method, die-casting aluminum painting plays an important role in improving the quality and added value of aluminum alloy parts.
Second, product characteristics
Paint spraying process and technology
Die-casting aluminum spraying mainly adopts high-pressure airless spraying technology to evenly spray paint on the surface of die-casting aluminum parts. This technology has the advantages of high efficiency, even coating, saving paint, and so on. At the same time, the sprayed coating can effectively improve the corrosion resistance and wear resistance of the parts.
Effects and improvements brought about by painting
After painting, the surface of die-cast aluminum parts is smooth and beautiful, which improves the added value of the products. At the same time, the paint coating can isolate the metal surface from the external environment and reduce corrosion and oxidation. In addition, painting can also enhance the wear resistance of the parts and prevent scratches and damages.
Scope of application of spray paint and application suggestions
Die-casting aluminum spray paint is suitable for all kinds of aluminum alloy die-casting parts, such as automotive parts, engine parts, electronic product shells, and so on. For some precision parts, such as aviation engine blades, etc., high-viscosity, low-solid paint should be used to ensure the stability and quality of the coating.
Third, the use of methods
Pre-treatment
Before using die-casting aluminum spray paint, aluminum alloy parts should be cleaned to remove surface oil and impurities. At the same time, check whether the surface of the parts is flat; the existence of pores, cracks, and other defects in the part should be repaired and polished. In order to improve the adhesion of paint, you can also carry out surface treatments on aluminum alloy parts, such as chemical treatment, mechanical treatment, and so on.
Paint spraying steps
- Paint mixing: choose the right type and color of paint according to the need, and mix it according to the instruction manual of the paint. Common brands and types of paints include polyurethane paint, epoxy resin paint, acrylic paint, and so on. Select the appropriate color and concentration according to the need, and pay attention to the specific gravity and mixing ratio of the paint when mixing.
- Spraying top coat: Pour the prepared paint into the spray gun and spray evenly on the surface of aluminum alloy parts. When spraying, pay attention to control the pressure and distance of the spray gun, so that the paint can evenly cover the surface of liga de alumínio parts. Generally, it is necessary to spray more than two times to get a thicker coating.
- Drying: natural drying at room temperature or baking drying, the general drying time is 10-20 minutes. During the drying process, pay attention to the control of temperature and humidity to avoid blistering, cracking and other phenomena of the coating.
Precautions
- Maintain good ventilation: Avoid prolonged contact with paint during the spraying process to minimize the hazards to the body. Ventilation equipment, such as exhaust fans and air purifiers, should be installed at the painting site to reduce the concentration of paint in the air.
- Pay attention to fire safety: paint is flammable, and fireworks should be strictly prohibited at the spraying site, and appropriate fire fighting equipment should be equipped. For the waste paints and solvents, they should be disposed of properly to avoid causing fire or polluting the environment.
- Quality control: for mass production of aluminum alloy parts, the quality of spraying should be checked regularly, and unqualified products should be reworked or scrapped in time. When carrying out quality inspection, visual inspection, scratch test and other methods can be used to assess the coating adhesion, flatness and other indicators.
Aluminum die casting products why choose to paint
Aluminum die casting parts choose paint as the main reason for surface treatment is: paint can protect and decorate the surface of aluminum die casting parts, improve the added value of the product.
Specifically, aluminum die casting parts may choose to paint in the following cases:
- Anti-corrosion and decorative requirements are high: painting can be used as a protective layer to improve the corrosion resistance and weather resistance of aluminum die casting parts, and at the same time, it can beautify the surface of the product and enhance the attractiveness of the product’s appearance. For example, aluminum furniture used outdoors, building facades and other occasions that require anti-corrosion and decorative properties.
- Used in high-temperature environments: Paint can be used as a high-temperature-resistant protective layer to protect the surface quality of aluminum die casting parts when used in high-temperature environments. For example, aluminum engine parts and heat exchangers used in high temperature environments.
- Specific functional requirements: paint can give aluminum die casting parts specific functions, such as insulation, thermal conductivity, anti-slip and so on. For example, aluminum parts used in electronic equipment, medical devices and other fields.
- Hide surface defects: paint can hide some tiny defects on the surface of aluminum die casting parts, improve the appearance quality of the product. For example, for the surface quality requirements of higher aluminum artwork, gifts, etc..
It should be noted that before painting, the surface of aluminum die-casting parts need to be properly treated, such as cleaning, de-oiling, descaling, etc., in order to improve the adhesion and durability of the coating. At the same time, different varieties of paint and coating process have different effects on the quality and effect of surface treatment of aluminum die casting parts. Therefore, in the actual application, according to the specific conditions and performance requirements of aluminum die casting parts need to choose the most suitable paint varieties and coating process.
In addition to paint, there are other surface treatment for aluminum die casting parts?
In addition to paint, aluminum die casting parts have other kinds of surface treatment can choose.
- Electroplating: is a common rust prevention method, can form a layer of corrosion-resistant plating on the surface of aluminum alloy die casting, and has good corrosion resistance and decorative, but also can improve the aesthetics of the product.
- Anodic oxidation treatment: can enhance the corrosion resistance and hardness of aluminum die casting parts, at the same time for the surface of aluminum die casting parts to provide a layer of solid protective layer, with good wear resistance and insulation.
- Spraying: it can be used for decoration, protection and marking, etc. Painting can hide the tiny defects on the surface, make the die-casting parts get a beautiful and smooth surface, and improve the corrosion resistance.
- Electrostatic spraying: it can make the die casting get a beautiful and smooth surface and improve the corrosion resistance.
- Oxide film treatment: aluminum and aluminum alloy in acidic or alkaline electrolyte selective autolytic properties, aluminum die casting parts surface leveling and polishing to reduce surface roughness and PH value, improve its beauty.
- Laser cladding: forming a layer of high hardness, high wear-resistant, oxidation-resistant and corrosion-resistant coating on the surface of aluminum alloy.
- Water-soluble coating electrostatic spraying: an environmentally friendly surface treatment method, suitable for anti-corrosion protection and decorative role.
In general, the surface treatment of aluminum die casting parts of a variety of ways, the specific choice of which treatment, according to the product use environment, performance requirements and production costs and other factors for comprehensive consideration.
Fourth, the summary
Die casting aluminum spray paint as a surface treatment method, in aluminum alloy die casting beautification, protection and repair has an important role. Through reasonable use method, it can effectively improve the use performance and appearance quality of liga de alumínio parts. In the process of use, attention should be paid to safe production and environmental protection to ensure the quality of the product and the sustainability of the production process.
