Die casting is a manufacturing process that uses high pressures to force molten metal from a crucible into a metal jacket. The material is then injected through a rod into a preformed mold (die). Once injected, the part is cooled, solidified and removed from the mold. This process is used for both parts and ingots.
The manufactured parts are characterized by high uniformity, good surface finish and high dimensional accuracy. The dimensions of the parts vary depending on the specifications. Weights range from a few grams for the smallest parts to several tons. We can even obtain extremely thin-walled parts. In fact, most of the parts do not need the final machining process or need very light machining.
Types of die casting
The two main types of die casting are:
- The hot chamber process: The injection system is immersed within the molten metal in the crucible, which in turn is an integral part of the machine.
- The cold chamber process: The material is fed from an external crucible to the injection sleeve, where a hydraulically operated plunger pushes the metal into the mold.
Within these 2 categories we have some variations: Die Casting, Vacuum Die Casting and Press Casting.
In Gestión de Compras we are professionals in a wide range of casting products, besides having the versatility to obtain parts of products under drawing.
We have the support of factories equipped with all the necessary tools to obtain the desired product at the best price. Starting with the melting of material, injection, solidification and expulsion of the finished part. We also guarantee that the necessary post-treatments are carried out on the parts.
- High efficiency. Die casting machinery has a high productivity compared to other processes.
- The alloys used in die casting have a long service life, easy to machine and automate.
- Final quality. The dimensional accuracy of the casting is high, generally equivalent to 6 ~ 7, even up to 4.
- Good surface finish, which means that further finishing will not be necessary; lowering prices per part.
- High strength and hardness, generally higher than sand casting by 25 ~ 30%, but extended, the rate is reduced by about 70%.
- This process allows complex thin-walled castings. For example, current zinc alloy castings have a minimum wall thickness of 0.3 mm; aluminum alloy castings up to 0.5 mm; the minimum casting hole diameter is 0.7 mm, and the minimum pitch is 0.75 mm.
- The main disadvantage of die casting is its high cost. Both the necessary casting equipment and the dies and related components are very expensive compared to most other casting processes.
- The process is limited to high-flow metals. Fluidity failures can lead to increased scrap rates, and scrap costs in die casting are high.
- Die casting involves a large number of parts, so repeatability issues are especially important.
- Die casting weights have previously been limited to between 30 grams (1 oz) and 10 kg (20 lb), but as of 2018, parts up to 80 kilograms have become possible.
- In the standard die casting process, the final part will have a small amount of porosity. This prevents any heat treatment or welding, because the heat causes the gas in the pores to expand, leading to micro-cracks inside the part and surface exfoliation. However, some companies have found ways to reduce the porosity of the part, which allows welding and heat treatment to be limited.