Hybrid technology – combining materials from different worlds

Linguistically speaking, the word “hybrid” has different origins. It is taken, on the one hand, from the Greek, where it has such meanings as “arrogant”, “exaggerated” or “presumptuous”. Hybrid technology does not have anything in common with this, however.

The word has its roots in Latin, where it means a blend of diverse things of two different origins. Here is an example to demonstrate what is meant by this: the word “automobile”.

It not only fits in the context very well; it also gives an excellent explanation of the meaning of the word. It is made up of two parts – “auto” and “mobile”, i.e. two basically distinct words. That is not what is important here, however; what is decisive is instead the fact that “auto” is a word based on the German language, while “mobile” is based on Latin – words of two different origins.

Other examples?

Hybrid cars are designed in such a way that they can use two different energy sources to drive: liquid fuel and gas or liquid fuel and electricity. Applications in space travel use similar names. Rockets that use both solid and liquid fuel for drive purposes are known as hybrid rockets. Or: hybrid computers are computers that operate with both analog and digital technology.

In traditional design methods, metal and plastic are normally fierce rivals. Hybrid technology takes specific advantage of the properties of both materials by combining them in a moulded part. The following explanation gives a description of a particular application where this is the case:


Fokus on hybrid technology

At the end of 1997, the front end of the Audi A6 was manufactured for the first time as a hybrid structure involving the combination of sheet steel and polyamide. A key feature of the hybrid structure: the specific properties of the materials used are not lost; they complement each other instead. What is created is a composite material with physical properties that could not be achieved with homogeneous materials.

The manufacturing operations are also based on the combination of two production processes: deep drawing of the metal and injection moulding of the plastic. As a result of this, not only the properties complement each other but also the economic methods of mass / series production.

So how does this technology work? Put in simple terms, perforated sheet steel is put in an injection mould and a suitable plastic is then injected around it in the mould. The molten plastic penetrates the openings perforated in the sheet steel – the metal is enclosed completely as the layers of plastic on both sides join together to cover the metal entirely. A comprehensive and very strong bond between the two components is created in this way – without additional adhesives or tie layers.

This technology has numerous advantages. As far as the constant demand for a reduction in the weight of components is concerned, load-bearing metal structures can be designed to have even thinner walls: with the help of carefully injection-moulded plastic ribbing, the tendency of thin structures to buckle and bulge under stress can be reduced substantially. The components maintain their load-bearing properties, even though their weight is being reduced. In addition to this: it can be demonstrated that the plastic structures increase the performance of the metal structure when it is bent or pressure is applied to it. In other words: compared with conventional components that consist of only one or other of the materials, the “perfect couple” – plastic and metal – have considerable advantages when combined.

Fibre/plastic composites – another material produced on the basis of hybrid tech-nology – have further unsuspected potential.