Die casting is an extremely versatile process. Molds, also known as dies, can be designed with almost infinitely complex shapes and geometries. Depending on the function of the casting it could be complete after ejection and trimming. Other castings require more processing after the gates, overflows, and vents have been trimmed.
Some features, such as internally tapped holes, cannot be die cast. Secondary machining procedures can be used to form these features.
Castings may require plating or painting also. When plating or painting is necessary on a casting it is important to maintain a smooth finish on the surface of the casting. Painting or plating will magnify any surface defects.
There are different branches of metal work. One branch involves the cutting, forming, joining, or sealing metals in their solid state. Castings are another branch, in which objects are made by pouring liquid metal into molds and allowing them to cool. These two branches of metal work may be separate, but metal items usually have both casting and working as part of their history.
Machine-worked metals often begin their journey as billets, slabs, or blooms from a continuous caster, or as pipes or wheels from a centrifugal one. This “casting” stage in worked metal is limited and simplified, and is usually referred to as metal production, but it is technically a casting of the raw materials.
On the other side, most castings are worked in their finishing stages. Sand castings generally have a rough finish, and often parts of the casting will be machined to be smoother, or the right size. Many iron and steel castings will rust if not sealed in some way and protecting against this oxidization is another almost universal finishing step. Home chefs have the experience of completing this step when they bring home a cast iron pan home and “season” it with oil. This is a consumer-finished form of secondary processing, but similar treatments can be done by the foundry.
In most cases, a die cast product has to undergo the last processes called surface finishing prior to its assembly. The surface finish can offer durability, protection, as well as a decorative appearance to a die cast component. Since surface finishing choices range from the appearance to performance, always it is better to communicate your application requirements with your die caster during the design stage itself. That is because specific features of several die-cast component designs affect the surface finish quality. For instance, the parting lines, gates, and ejector pins can affect the output. Therefore, it is better to evaluate your best design as well as surface finishing options with due consultation with your die casting partner.
Many different types of surface finishing options are offered for die-cast parts. Generally, die casters can handle various surface finishing requirements. Depending on your requirement, any of the following shall apply.
The anodizing output is a protective coating that is non-conductive and seals a die-cast component. It comes in an array of colors and is an extremely affordable choice to improve durability as well as resistance to corrosion of the part.
Powder coating is one of the popular surface finishes out there. It is tough to achieve as it is cured at relatively higher temperatures. In general, it is ding and scratch resistant. It is available in many different colors, textures, as well as gloss levels. Considering that it is appropriately cured, an extremely controlled die casting procedure is important.
The vibratory finishing technique allows to deburr, burnish, clean, as well as brighten workpieces or parts. During this surface finishing process, components are put into a vibratory machine to obtain the preferred effect. The contents are vibrated as part of that. The process can finish the internal features of a component, like holes, as well as is less loud and faster.
Impregnation seals the porosity in metal components. It creates watertight parts. It is an extremely viable surface finishing option to enhance the yield as well as reduce the scrap. Plus, it is a wonderful option to use post machining when removing a die-cast component’s ‘skin’ to make it leak-free.
Polishing requires abrasive tools’ use in order to smooth the surface of a component. It is usually performed by abrasive discs or belts and is used to level the surfaces, get rid of scratches as well as pits, and polish a part’s surface leaving a lined or brushed finish.
Surface Finishing at JINGXIN Die Casting
JINGXIN Die Casting handles the various surface finishing requests from our clients through our secondary department. We have a rich and varied clientele who seek surface finishing for die casting applications or projects. Prior to entering into a project with us, have a conversation with one of our engineers to choose the processes better suited to your application.
Give your part that “final touch”. JINGXIN Die Casting’s secondary department can handle many different requests.
The secondary shop can accomplish these processes and more:
- Powder coating
- Media blasting
- Vibratory finishing
- Brush Finishing