In our daily lives, I believe everyone is no stranger to aluminum alloy products. From small perfume aluminum caps to the frames and shells of some products, and even to some chassis accessories of new energy vehicles, etc., aluminum alloys are all applied in these. Most of these product accessories are produced through the die-casting process. Do you know what surface treatments are done on these die-cast aluminum product accessories?

I.Grinding and Polishing

Applicable Scenarios:

1.Products with high appearance requirements that pursue a smooth and shiny surface texture, such as high-end exterior parts.

2.Accessories that need to reduce the surface roughness and have high requirements for surface flatness, such as some precision components.

Advantages:

1.After grinding and polishing, the surface finish of the product can be improved, making the product appearance highly glossy and shiny, enhancing the appearance of the product.

2.It can improve the flatness of the product surface, reduce surface defects, and improve the dimensional accuracy of the product, thereby enhancing the quality and performance of the product.

Disadvantages:

1.The cost is relatively high. Especially for some die-castings with special shapes, the difficulty of grinding and polishing will be relatively large, and the labor cost and time cost will also increase accordingly.

2.Generally, grinding and polishing will remove some materials. For accessories with high requirements for dimensional tolerances, the polishing allowance needs to be precisely controlled. Otherwise, it may affect the assembly accuracy of the accessories.

3.Although the surface is smooth after grinding and polishing, it may still be oxidized at room temperature. Therefore, additional surface treatments such as passivation, electrophoretic coating, powder spraying or oil spraying are often required.

II.Passivation and Whitening

Applicable Scenarios:

1.Applicable to die-cast aluminum accessories that need to improve corrosion resistance, especially products used in humid or corrosive environments, such as automobile spare parts and outdoor product shells.

2.More suitable for parts with a requirement for a silvery-white surface color and a certain metallic texture.

3.Applicable to products that need to enhance adhesion. The passivation film can provide a good adhesion foundation for subsequent surface treatments such as spraying and printing, making the coating more firm and durable. For aluminum alloy products that need surface coating, it can improve the quality and service life of the coating.

Advantages:

1.It can improve the corrosion resistance of die-cast aluminum products by forming a passivation film on the surface to prevent the erosion of oxidation and corrosive media.

2.It can obtain a uniform silvery-white appearance, making the product look simple and clean.

3.Compared with some complex surface treatment processes, the passivation and whitening process is relatively simple. It does not require complex equipment and high investment. Meanwhile, the passivation liquid can be reused, reducing the production cost.

Disadvantages:

1.The thickness of the passivation film is limited. Compared with other surface treatment processes (such as powder spraying or oil spraying), there is still a certain gap in corrosion resistance. In some extreme corrosive environments, additional protective measures may be required.

2.The appearance effect is relatively single, mainly white or close to white, and cannot meet the requirements of some products for color diversity. If other colors are needed, additional surface treatments are required.

III. Powder Spraying

Applicable Scenarios:

1.Applicable to products with high requirements for durability and wear resistance, such as outdoor products and shells.

2.Products with relatively high requirements for color diversity, powder spraying is a good choice, such as shells and plates.

Advantages:

1.It provides color diversity and can meet the personalized needs of customers.

2.The coating has good durability, wear resistance and corrosion resistance, which can effectively protect die-cast aluminum products for long-term use in extreme environments.

3.The cost of powder spraying is lower than that of oil spraying.

Disadvantages:

1.For die-castings with complex shapes, there may be a situation of uneven powder spraying, which needs to be optimized.

2.The appearance of powder spraying is not as beautiful as that of oil spraying.

IV. Oil Spraying

Applicable Scenarios:

1.For products with high appearance requirements, oil spraying can be chosen, such as high-end product shells and ornaments, which can achieve high gloss, metallic texture, pearlescent effect, etc.

2.If the product needs to be waterproof and moisture-proof, oil spraying can provide certain protection.

Advantages:

1.It provides color diversity and can meet the personalized needs of customers.

2.Compared with powder spraying, oil spraying can form a relatively uniform and smooth protective film, improving the waterproof, moisture-proof and insulating properties of the product.

Disadvantages:

1.The solvents used in the oil spraying process may have a certain impact on the environment and human health, and ventilation and environmental protection measures need to be taken.

2.Compared with powder spraying, the wear resistance and durability of the coating of oil spraying may be slightly worse, and fading and peeling may occur after long-term use.

In conclusion, there are multiple choices for the surface treatment processes of aluminum die-cast  products. We can judge and choose the appropriate surface treatment process according to its application scenarios, functions or performance requirements, etc.