Fascinating Precision in Metal – An Introduction to the Die Casting Process

Efficiency in manufacturing is a crucial factor. Especially in the automotive industry, mechanical engineering, and electrical engineering, components are needed that can be produced precisely and to exact dimensions in large quantities. This is where the die casting process comes into play – an established yet fascinating manufacturing method that shapes metal.

What exactly is die casting?

Die casting is a formative casting process in which liquid metal is forced at high speed into the cavity of a metallic permanent mould, also called a die. There, the liquid metal solidifies under high and adjustable pressure. After the metal has solidified, the finished component is ejected from the mould and the process starts anew.

Die casting is particularly suitable for the series production of complex and dimensionally accurate parts – thanks to the high level of detail reproduction, often with minimal post-processing.

Typical materials in die casting: aluminium, zinc & co.

Typical die casting materials are non-ferrous metal alloys such as aluminium, brass, or zinc. These materials are characterised by good flow properties and mechanical strength, making them ideal for the die casting process.

Depending on the material, different properties arise: aluminium scores with low weight and good thermal conductivity, zinc with high dimensional accuracy and excellent castability, while brass is valued for its high strength and corrosion resistance. The choice of a suitable material always depends on the requirements of the component and its intended application.

The process steps of die casting in detail

To produce cast parts using die casting, a die casting mould is always necessary. The mould usually consists of two halves with corresponding inserts, in which the respective cavities – these are the hollow shapes representing the future contour of the cast part – are embedded. These inserts are manufactured with high precision and equipped with cooling channels so that they are temperature-controlled.

1. Preparing the mould in die casting

In die casting, a release agent is sprayed onto the mould surfaces by machine before casting to prevent the liquid metal from sticking and to extend the mould’s service life. Afterwards, the machine closes the two mould halves. The mould is now shut.

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2. Dosing and melting the metal

The selected metal is heated in a furnace to melting temperature, liquefied, and held at the desired temperature. Depending on the machine type, the metal is either melted directly in the machine or processed externally and then filled into a casting chamber. For this purpose, a predefined amount of liquid metal is taken from the crucible and dosed into the filling opening of the casting chamber.

3. Injecting the molten metal

After a short dwell time of the previously dosed melt in the casting chamber, the chamber slowly moves towards the mould, gradually compressing the liquid metal. When a pre-set point is reached, the casting machine accelerates the plunger to a high speed, filling the mould cavity with the molten metal.

There, the injected melt solidifies under high, adjustable pressure.

4. Solidification and cooling of the die-cast part

As soon as the liquid metal has filled the mould, the solidification process begins. The metallic mould ensures rapid cooling due to its high thermal conductivity and targeted temperature control (via cooling channels), resulting in a fine microstructure and good mechanical properties in the part. This effect is supported by the high pressure exerted by the plunger on the melt, which is maintained during solidification.

Man with yellow glves puts metal piece in a machine

5. Demoulding and post-processing

After solidification and a completed cooling period, the mould is opened and the cast part is ejected mechanically or pneumatically using so-called ejectors. Depending on the application, further steps such as removal of runners, deburring or surface treatment follow. The die casting process then starts again.

Advantages of the die casting process and typical application areas

Die casting offers high dimensional accuracy, smooth surfaces, and the ability to economically produce thin-walled, complex geometries. Die-cast parts are found in engine housings, transmission components, electronic parts, and increasingly also in medical technology or consumer product housings.

Another advantage of die casting is its high repeatability – once optimised, the process delivers thousands of identical parts with consistent quality. Modern die casting systems also enable the integration of automated processes, such as automatic deburring or quality control through sensors and image processing.

Conclusion: Die casting brings metal to perfection

Die casting is more than just a technical casting method – it is a key to series production of precise metal parts, combining craftsmanship and high-tech. For industries focused on lightweight construction, high strength, and cost-effectiveness, die casting is often the first choice. And anyone who has seen glowing liquid metal transformed into a functional component in seconds will understand why this process has been a mainstay of modern manufacturing for decades.