No, we will not talk about amphibians from Opel. It just might happen that the company's future cars will become … lighter than water!
Do we have a return to wooden structures? Not at all. Designers and technologists of Opel are preparing to use a completely new material - sponge (or porous) aluminum. Two main technologies for preparing amazing floating metal have been developed. According to one of them, argon or nitrogen is fed into a crucible with a melt, liquid aluminum foams and solidifies in this state. This, of course, is a greatly simplified description of the process. In fact, there are many subtleties that, in fact, constitute carefully know-how that is carefully guarded from competitors. For example, to stabilize the foam, ceramic particles have to be added.
The second technology consists in pressing a mixture of aluminum sawdust and a binder, followed by short-term heating to a high temperature, at which the “glue” evaporates, leaving many pores in its place.
The result is one - it turns out, as it were, a solid aluminum sponge with a density of … 0.07 to 0.6 g / cm3. (Recall: the density of water is equal to unity, and of monolithic aluminum - 2.7 g / cm.s.) This poroaluminium has high strength characteristics and is suitable for the manufacture of not only interior parts of the car, but also such supporting structures as thresholds, subframes, suspension arms, body racks. Today, porous wishbones are being successfully tested: they withstood four times the standard resource at the stand, without showing signs of fatigue failure.
However, it is not only the extreme ease of the new material that attracts. The porous structure absorbs deformation energy well, which promises a breakthrough in ensuring passive vehicle safety in a collision. Moreover, having significant internal friction, poroaluminium effectively dampens vibrations and absorbs noise. In short, it may turn out that we are on the verge of a real technological revolution in the automotive industry. Provided that it will be possible to solve many completely new problems. For example, it will be more difficult to optimize the suspension characteristics: after all, the relative difference in the mass of an empty and a passenger-filled car will increase sharply. Five hundred kilograms of payload against the background of a ton of car weight is not at all the same as the same five hundred against, say, two hundred. Such ratios are not uncommon for trucks, but remember whether it is pleasant to drive in an empty KamAZ.