In die casting, zinc die casting finishing process might improve the product appearance and performance. Zinc die casting parts can be submitted to different kinds of post treatments for many reasons, such as improving a product appearance, conferring resistance to chemicals, corrosion and wear, improving or modifying electrical conductivity and removing burrs and other flaws.

Choosing Zinc Die Casting Finishing Processes

In order to meet clients’ requirements the Die Caster can chose in a range of finishing process.

However, before applying a zinc die casting finishing, is crucial to prepare product surface because sometimes with many surface treatments imperfections or defects caused by die casting process are not covered but emphasized.

For all these reasons, as mention before, clients should deal with suppliers involved in the process since the very first phase and that apply a co-design activity.

In fact it is impossible to define all production cycle in distinct phases, but it is really important to consider it as a flow of phases. This is even truer in finishing terms.

Each zinc die casting finishing process has its own characteristic and a cost, which sometimes can be even higher than die casting manufacturing itself. However, they can boost some casting properties and improve the surface look.

To balance these costs and to make this deal more profitable, during the early phase of a project, customer and supplier should work together in a co-design activity.

Co-design is a service provided by suppliers, where the collaboration with their clients is fundamental in order to obtain a product aligned with technical and aesthetical requirements.

In fact during Co-Design the Die Caster can contribute from his experience to the initial mold design phase and regarding decisions related to production process. During this phase, product requirements are defined and the right finishing method is selected, in collaboration with the client.

An essential part of co-design, during first steps, is simulation analysis that, applied by qualified die casters, can predict molten metal flows and the result of the die casting process. This allows optimizing the mould structure. Furthermore simulation, using tools such as MAGMASOFT software, can predict any possible defects or issues already during product design phase.

All these steps should be done bearing in mind that the collaboration between supplier and client is crucial for the good product outcome.

In addiction co-design can be applied to combine the finishing method and the way it is applied that makes the real difference in terms of product quality and production costs. Here comes the experience of high qualified Die Caster that can choose a lower cost treatment but apply it in a way that satisfies customers’ requirements.

A selection of Zinc Die Casting Finishing

As said before zinc die casting finishing can be applied for different reasons: to improve aesthetic side of a product, to improve corrosion resistance, wear and chemical resistance, remove burrs and flaws and modify electrical conductivity.

Among the variety of finishing processes we can include:

Thermal deburring and post-cast processes are used to

• smooth and brighten surfaces
• round sharp edges
• remove flashes

• protect against corrosion
• dissipate heat
• seal
• insulate
• boost the surface performance
• ionize
• aesthetic requirements

Depending on the customers’ requirements and specifications regarding durability, protection and aesthetic appearance, most Zinc die cast components can receive from one to three standard zinc die casting finishing processes.

To know more about these kind of finishing and features please feel free to contact us at: Contact 

Steps of zinc die casting finishing process

Now, let’s have a look at finishing steps once the element is ejected from the mould:

1. Deburring phase
2. Application of surface conversion coating
3. Application of final surface finishing

Deburring

Vibratory processes can round sharp edges, remove burrs, loose flash and debris, and smooth and brighten part surfaces. Most die casting components go through a mechanical deburring operation right after they are ejected from the mould.

Surface Conversion Coating

After deburring, a conversion coating can remove any remaining oil, agents, and other contaminants. Coating can act as preparation treatment and primer if painting is required, and as the product’s final finish.

Final Surface Finish

A wide range of treatments are available to maximize

• corrosion resistance
• heat dissipation
• under abuse surface performance
• insulation properties

A final zinc die casting finishing process can include powder coatings and water-based appliances.

Hereunder a selection of the most common final surface finishes:

• Powder coatings for die castings are aimed at producing a durable and uniform surface finish, in a wide range of colours.
• Polyurethane and water-based wet paints are considered final colour finishing processes as they require shorter time and less production costs than powder coatings.
• Electroplating is the process of electro-deposition of a metallic coating on a component. It provides wear and corrosion-resistant finish to any surface. In addition it is possible to divide it in : 
• Copper-Tin-Zinc electroplate gives the zinc surface a dull and silvery finish.
• Copper-Nickel-Chrome electroplate is one of the best finishing as it protects zinc surface against acidity of subsequent baths, uniforms the finish, and assures a good electrical conductivity. 
• Mechanical Plating combines mechanical and chemical actions to reach the desired coating thickness. It can be applied on all surfaces, even on inside corners. The parts are placed into a drum with metal powders and a chemical activator, then they are tumbled.

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