While working with the finest non-ferrous metals, the element of engineering process guesswork is eliminated by adopting specialized casting techniques and methodologies that deliver aluminium components to match client specifications. Iron-free metals like zinc, tin, lead and magnesium possess unique properties that are brought to use by innovative product-shaping processes.
The most popular metals that are cast for industrial applications are aluminium alloys, copper-based alloys and zinc alloys. Non-ferrous castings can be made by using one of the following three processes; sand casting process, gravity process and high pressure die casting process.
Processes used in making Non-ferrous castings
- Sand casting process
Considered as one of the simplest mediums for the production of non-ferrous castings, the sand casting process is the most economical process of the three. The castings take shape by pouring molten aluminium, zinc or copper into a sand mould.
The sand casting process is chosen for a few reasons like; producing a small number of castings, for castings with complex or intricate shapes or for huge castings.
With a sand mould, the largest casting sizes can be achieved as they have general versatility. The disadvantage however is that the production times are longer than the other two processes.
- Gravity die casting process
The gravity dies casting process makes use of steel or cast iron moulds that allow aluminium or zinc castings to be produced more accurately and at a lower cost. A better surface finish, as well as excellent mechanical properties, can be achieved through this casting process.
When it comes to the tooling cost, it is a fraction of what is needed for pressure die casting. Non-turbulent mould filling ensures that the production of gravity castings possesses minimal porosity.
Gravity dies casting machines usually have a range of microprocessor-controlled hydraulics that mechanise the movements of the die. They offer tilt pouring and up to four axes of hydraulic movements.
- High pressure die casting process
High pressure dies casting is the shortest route from molten metal to the completed component. It is done by injecting molten metal into a sturdy steel mould and allowing it to solidify under the pressure created inside the mould before ejecting it.
The high pressure dies casting process allows precise, quick and cost-effective die casting production using aluminium or zinc as raw materials. This process meets the needs of hi-tech industries where dimensional tolerances and product appearance are critical.
Most high pressure die casting machines have locking forces that range between 220 and 530 tonnes. The other features of this process include automatic ladling, real-time shot control, automatic casting extraction and cooling.
Aluminium castings produced using one of the above-mentioned processes have applications in the automotive industry for cylinder heads, engines and manifolds. They are also used in electrical appliances, cooking equipment and food packaging industries.