Die Casting Surface Finish and Treatments Used in Automotive Components

Die casting process is preferred in the automotive industry due to the stringent requirement of aesthetic and functional properties in the design of a component. During the die cast process, the manufacturer applies certain techniques for shielding the component against any external agents. All of the components used in the automotive industry undergo such surface finishes for enhancing its functional and aesthetic qualities. The position of the component in the vehicle is the crucial aspect that determines the die casting surface finishes applied onto it.

Functional treatment is undertaken for components that are deployed inside the vehicle. A visibly positioned component requires aesthetic treatment for obtaining quality in the design aspect. Various kinds of die casting surface finishes are used for enhancing the functional and aesthetic qualities of an automotive component. Given below is a look at the die casting surface finishes and treatments used for automotive components.


Chromating is described as a process of applying conversion coating in order to prevent oxidation on the component. The process is different from the galvanic method and involves exposing the product surface to various products. A protective layer is created on the surface after the component is subjected to this finishing process. When this layer comes in contact with air, it enhances oxidation resistance and further shields the materials from white corrosion.

Chromating is applied mostly in the final step of the production cycle. In some cases though, this is also carried out before the application of other finishing processes. For example, car air vents louvers undergo chromatin treatment before it is painted. This ensures that the component is resistant to oxidation and temperatures along with its aesthetic quality.

Tech Seal

Tech-seal treatment is applied on components that require resistance to abrasion and surface defects such as scratches. This process involves an organic water-based treatment allowing the product to develop increased resistance to corrosion. While undergoing this treatment, the product is colored along with adding the required friction coefficient.

Tech seal is mostly employed in the opening and closing mechanism of the sunroof. This improves the resistance of the component to impact and minimizes friction that facilitates good sliding movement.

Black Zinc

Black zinc is a protective and decorative treatment applied to the component for providing a glossy and uniform black finish. Black zinc treatment offers excellent aesthetic qualities to the components and allows in matching the color with other components.

This process also provides SSL resistance and uses an oil sealing treatment for uniform application of the color. In addition, black zinc process also enhances the resistance of the component to impact and scratching.