EN-755-9 and EN-12020-2 are the accepted norms for the extrusion of aluminium profiles. They permit deviations of ±0.15 mm or more. Mifa ignores these norms and applies precision extrusion to an accuracy of 0.02 mm and final processing such as surface treatment and assembly. This is unique in the aerospace industry! It provides countless possibilities for extrusion profiles and aerospace components.
Aerospace industry benefits from customized extrusion
Bulk production, standard work, and inaccurate are words often used by engineers when asked to describe the characteristics of extrusion. But there is another option. Mifa can supply batches in small to large volumes, and we offer custom-built products and precision, also with regard to straightness, torsion, concentricity, parallelism, surface roughness, and fit. Add to this the outstanding features of aluminium – post-processing is often not needed – and it becomes clear that precision extrusion is suitable for a host of applications. It can also be used as a replacement for other technologies and materials.
What is extrusion?
This is a summary of the process. Moulders produce a mould based on blueprints of the profile. This mould is then entered into the extrusion machine. An oven heats a solid rod of aluminium – or magnesium – to several hundred degrees Celsius. As soon as the material is soft enough, it is ready to be pressed through the mould. This happens under high pressure. At the other end of the mould, the aluminium comes out in the shape of the mould profile. The aluminium is then cooled and – as soon as all the basic material has been pressed through the mould – straightened. After that, the material is sawn into pieces for further treatment if necessary.
Precision extrusion: four key factors for the aerospace industry
Precision extrusion is, as the name implies, very precise work. Mifa frequently uses this precision method for its customers such as Airbus, Diehl, and Boeing. Control of the pressing process, of the flow of aluminium through the mould, is crucial. For this, four factors are important:
- Knowledge of the elements of the aluminium alloy. Pressing the desired aerospace profile requires a perfect composition of materials. Mifa uses the following alloys which are important for the aerospace industry: 6061, 6082, and 7075.
- Not only is it important to press the aluminium at the right temperature, it is also essential that the block of aluminium has the same temperature throughout. The temperature after pressing and the cooling process determine the mechanical values of the aerospace profiles.
- Pressing speed and pressure should be entered with great precision, depending on complexity, precision, and alloy type. This is a delicate job – especially with asymmetrical profiles, as it is impossible to supply the same pressure on all sides.
- The construction of the mould. The mould should have the right shape and be able to handle the pressure.
Knowledge of lightweight materials specifically used in the aerospace industry
We have built up almost forty years of knowledge and expertise in all four of these factors. They allow us to achieve – and guarantee – a high level of precision. Not only for common alloys such as 6060, but also for 6061, 6082, and 7075, which are important for the aerospace industry, as well as plenty of others. We achieve the same level of precision for magnesium alloys for customers such as Airbus, B/E, Diehl, and Zodiac.