A material that has been known for decades has been reworked to meet new applications in the automotive industry.
This is what Georg Fischer Automotive has done with the well-known material cast iron. The result is known as SiboDur.
The new material’s name reflects both its “ingredients” and its properties. The name SiboDur is derived from the silicon, boron it incorporates and from the material’s extreme durability achieved through a special manufacturing formula.
The material, used to date in the German plants of GF Automotive in Singen and Mettmann, reconciles what is actually irreconcilable: hardness and ductility. It is destined for use in passenger vehicles where its dynamic properties will be particularly important in the development of chassis parts.
The hardness of cast iron can be increased, as engineers have long known, by creating graphite precipitates in the form of spheroidal particles rather than flakes. Unfortunately, this also makes the material brittle. This problem can be dealt with by adding silicon, which makes the cast iron more ductile, but at the cost of castability.
The problem of castability was solved by adding boron, which helps the material solidify when it cools down.
Owing to the hardness of SiboDur, chassis parts can be made slimmer than those manufactured with aluminium. This relieves some of the concerns that automotive developers have when faced with designing parts for limited spaces.
The Volkswagen Group is already having a transverse link – which used to be forged – made of SiboDur and built into the various models of its VW, Audi, Seat and Skoda brands.
In a few years’ time, GF Automotive expects to be delivering some 50 parts from the SiboDur family of materials to the automotive industry.