Surface treatments of alloy die casting parts

The surface treatment of alloy die casting parts is divided into pre-treatment and post-treatment. The former treatment is to remove the oxidation skin and oil stains in the surface and to increase the adhesion of post-treatment and improve the appearance effect. The most commonly used pre-treatment of aluminum alloy die casting parts are shot blasting, sand blasting and phosphating. The post-treatment usually includes powder coating, oxidation, electroplating, and electrophoresis. Other surface treatments are applied only to products with special requirements for cost reasons.

Today please come with us to have a rough understanding about several surface finish treatments.  

Powder spraying treatment. Use spraying equipment to spray powder to the surface of the workpieces. Under the action of static electricity, the powder will be evenly adsorbed on the surface, forming a powder coating. After hot baking and flat curing, the coating become final power coating with different kinds of effect. The spraying effect of powder spraying is superior to that of paint spraying in terms of mechanical strength, adhesion, corrosion resistance, aging resistance and cost. 

Paint baking treatment: he real painting process is to phosphatize the aluminum alloy before spraying and baking. Such coating is not only anti-corrosion and bright wear-resistant, but also not easy to fall off.

The purpose of pre-painting treatment is to get a good coating. If not removing the grease, oxide rust, and corrosion substances on the surface which occur during manufacturing, processing, handling and preservation process, the performance and appearance of the coating will be directly affected. Therefore, pre-treatment plays a very important role in the paint baking treatment. The pretreatment includes oil removal, washing, rust removal, washing, surface adjustment, washing, phosphating, washing, and drying.

Oxidation treatment: Conducting oxidation is suitable for aluminum alloy parts, and anodic oxidation suitable for aluminum product and aluminum profiles. The oxidation color of aluminum alloy generally has natural color and sky blue. Anodic oxidation is carried out under the condition of high voltage piezoelectricity. It is an electrochemical reaction process. Conductive oxidation does not need to be electrified, but only soaked in a medicinal liquid, it is a pure chemical reaction. Anodic oxidation takes a long time, often a few minutes, while conductive oxidation takes only a few seconds.

Sandblasting treatment. A layer of fine sand is sprayed on the surface of aluminum alloy products to enhance the friction coefficient of the contact surface and enhance the reliability of the connection. Sand has different thickness and grains.

Electroplating treatment. Electroplating is the process by which a metal or alloy is deposited on the surface of a workpiece by means of electrolysis in order to form a uniform, compact and cohesive metal layer, which is called electroplating. A simple understanding is a change or combination of physics and chemistry. The application of electroplating technology is generally used for the following purposes: anti-corrosion, anti-decoration and anti-wear.

Sieg-Huao, as a professional alloy die casting manufacturer, has one-stop solution for your different requirements of surface finish treatment. What we need is just the drawing and we can return you a perfect die casting product. Looking forward to your inquiry!